Adding metadata

29 files changed, 22818 insertions, 0 deletions

diff --git a/dev-lang/rust/Manifest b/dev-lang/rust/Manifest
new file mode 100644
index 000000000000..8661a5e89a2a
--- /dev/null
+++ b/dev-lang/rust/Manifest
@@ -0,0 +1,78 @@
+DIST rust-patches-1.74.1-r101.tar.bz2 3887 BLAKE2B 0afb0252fe56ac8c572fe20acd989f9ef3f33cb8134cdb8fbf5cb064156556aedeb226fd50af465f35f656ebd0c0a163ca060490f44811def8535bad70f5f24d SHA512 7253728000d49fd8533182aa8961e70aef41a48e2df03e72d1ea93ca7abb924bbe1689692d874f2b18469e5a54ea572e55ddc18c9f4d81d1e8ec380f2d72095b
+DIST rust-patches-1.75.0-r101.tar.bz2 4419 BLAKE2B 389a688a6e92d5f9325bade125b006deb7453d9d7ae0483c8ec0cf580f95eb03a65f600e79ed354029b4b91ab8f66929877bdc6ebf83e7b8d3b1d9451fecd8b6 SHA512 6f36e9e13e590bff72483ea4364c045579858da5db3868048f79e0dd6ac896aaf00a1fb9d156820e742a1f5ec412ddfa897677133669b77a4f219c6d90365775
+DIST rust-patches-1.76.0-r101.tar.bz2 5513 BLAKE2B 52816dffac969520e7b73ceaae1201bb7abba129da1021e8e39ccd6e471281c51cf005221589c7b08fc328be54ba2d6134fc8e240cb15f0b877e370009937084 SHA512 a65d306d709e99c688e4febb439a60f9ac8b506a86fdb3021782dfbb8991ddcc07adcd19494a8e76233ad2bec7f23896b6eb80c13929b7c997fdc3fd45f8b63a
+DIST rust-patches-1.77.1-r101.tar.bz2 4937 BLAKE2B 2b6cdb6d61c7bde5cfaaeea4ae0076acc4d43375805567a48d10b4c9a622ad6234dc5725c30df7ab26d8d67566f405d89b1fff384f263cf3dd404e4298a53801 SHA512 e9d16860549f2698957cbd8dd46278a5706c630ff78b8d1199be1b9ba724e60e8ae7020b0a30695841f77053294c043e5957425573db709f30a7b40d4cb53613
+DIST rust-patches-1.78.0-r101.tar.bz2 4098 BLAKE2B a62ed3ca1b0ac51c6b0b01653b5ea6e831794de983f72714da36ba508aef655b9255498d7fd0c05c5034ef70a319fc00b913c0fb81f7ae17721ee53ff5e45f92 SHA512 cbe95306fe97224f2921a5846204d49a84276a38047ad8f8256fdd349fd45a63b3462810c75384b079e2141ebee3288987e9a4510e2605a5ecbb8612084694e9
+DIST rust-patches-1.79.0-r101.tar.bz2 4102 BLAKE2B 42c4202d778c286122bd00f758ad3ecc6c3fc2a3d8dda7bf49baec126a4ae1112846b0d1314d9331db99f762e971815fdd3b6e47fedb7a9ecedafbf2ffa08649 SHA512 7e518ccba28bafaf03e5512c4567e3b63d17a30e8df025a8ffe1d62c521db2986cdeb6a25cdacafe1e27d05eef01bed43ad42a9dc6a9d4bda1cf7cb98505673e
+DIST rust-patches-1.80.1-r101.tar.bz2 3609 BLAKE2B d13296fb44c1ab4b6bc6133b64baf7073b686f4a93b0a75cde4e73f90ee84d009ea9c931c9244081e2c86b40a91829f3768e27c339a4e3d457cb01756f689fe6 SHA512 8c9e0d06af8ce2387355a8917383686f05021b4313c9b4f0a1eaf1a81fb08323686cff6ce06e013b6919f25a50a2a5fb5d0c605740e46c68677c4d665c069b41
+DIST rust-patches-1.81.0-r101.tar.bz2 3607 BLAKE2B 7a200d740920b965f6ef97e23c1f0b20b5e0f055b0c3655c85d55cd11287c07c0c4b7149bccb4ab1a7982c5a8c75d8ad44272abac131f90bd9de161821548f80 SHA512 64af65287ed551143ba2bf2e6828e3ccdb5e92b393d8ad9fe9fa3e6b38c67c856f9e37caa9cf1441ce1c7a8e37e22d78f6d15d97713df66abd95798ae9d2da9f
+DIST rust-patches-1.82.0-r103.tar.bz2 5843 BLAKE2B 0083bdbdfdf564fab9709bdffadd99de024296619aace7a0cfd8cef080ec002452b8e20bb61a3a828d3ae0cd3d5174a04d89ee6351fc976f0678b9ff0dee4eaf SHA512 71296ae4991f67a5983c54800eed58b15ab0a25aa117f5ac56131f9c895014bbc42feab5cc319fd97f0fc64e7715e6b945715375bc32890e6bc5bb308ec0a5a1
+DIST rust-patches-1.83.0-r3.tar.bz2 5886 BLAKE2B e7506d4b2d137d7746bd85581170401a700dbedad7c1bb063fedbfd19021a7c6312d541d33dfc7444cfbee64bd3b904cbaf64233523f1e23743925868979b75f SHA512 0f79df5617f900420eacf1e100323defc8316ac3d7733a5ef127551cf6d6667e96bc337540a25f1d464d14e0b3815d66041a0bf7570f3279a978f6eef64dfccd
+DIST rust-patches-1.84.0-r2.tar.bz2 2507 BLAKE2B ffe4e5fc49deebdb8b8b3022f951dfeaad15c57c0afe17b050489ee19419f66be0bf4349b300a91c316bf669d22627c7270c013264aee176e846f5b2894f66f0 SHA512 bca8e22947c8f9073e3de67030372f326b94aea28dbdc57bfe0f35f40df2bc6380f519ffe2cc0f4014830bc9fcc902612ccf104768bde94da9e4989245e31601
+DIST rust-patches-1.84.1-r2.tar.bz2 2982 BLAKE2B 2f7addfa4530f3eab79f55ea44eee6390970874ae5ed40ef8706224024db47c861326dc5a79ed9bffcffbad5b27d44b6a3aebab7987fdb61124be3083fbabd71 SHA512 cc852e1e679827390134b47bfaa68567a75a5e8559a3caa24ab3931955050bac59f4fe6a4c249d83bde0aa25667ea04749f3763ff3566daa2999df8cbf2d0981
+DIST rust-patches-1.85.0-r2.tar.bz2 4462 BLAKE2B 61cfde8688fecab1a5c3c80f29b37b691581f3f8be1648f9db34fff15026dab426458cba3b9f06fc5606a0a878b0527698ea6f94c7dff014e4339154ac907d13 SHA512 317ab0bcbb792faa1a761893264a29bd650b0d6c5ab17aa762075daccfda684bc6cdd20c0ef89b51bde1a7384fb1df576b18b5303115a8cf04877b435b2d6491
+DIST rust-patches-1.85.1-r1.tar.bz2 4473 BLAKE2B fad2fe3222e2625b5cbc60ea1fb805080ce70f751c930c0e3bde9cf043059e1fc3ba4d8e618166fe99a7fcf12d5cccb684c05d4c2542a89c9794869204cbcb09 SHA512 edf680a1d3a29ae5d8140031dc8b232b747d08494db2f3393ccc286d9197139583bcaf536d5125b8c896a610c075115b9a16a6e6f3f6b5da60e58433f000dba6
+DIST rust-patches-1.86.0-r2-1.tar.bz2 6308 BLAKE2B eca644026942bd729a748df57dd67465bbec96b2d18a71c58fe04bb8e2514aabb1ca02cbd3761be5283328a3b728e063b1b85ea78f4f242c182071c44b8cb148 SHA512 1f1edcf76c64b0555366253e21d759e904a752746c2e5d88aba6e31f5ee2a2b0b06275674d2fc3acc42f589905eddc006d788f95b48a5d79a6ab767251d934da
+DIST rust-patches-1.87.0-r1-1.tar.bz2 5116 BLAKE2B 783ad21464a7e393d0aee506119be12b0137a7d360402b74f36b6fde154c2804cc0779da63875977d09f7e9f2d273ff41dd189bbe4eb239a314fea27bbaa704c SHA512 8c67e4e43bf2afb226f70bb2a03aad0abfd525cd484c8c9ff663da06d63b471f4f1b48169d952a6a6c14258c0029dedea14aadaaca2ee75389df65b806188363
+DIST rust-patches-1.88.0.tar.bz2 4062 BLAKE2B 64168ffa608f2edf2e0b3d079152c3b5dd59d0cea29078894f286bf91488e2e7769c55ede2d43769368d2147b46699d1bf981190d6800dc3d41c736289122eaf SHA512 b565acfb4d1146e52b1fb66b4a242927407cc34f1b38c2a100135cbbde24c8374af1997bc22069cca25f33cc8d747e56391f3d98a2d4e13dc0abcec0d6f88b0b
+DIST rust-patches-1.89.0.tar.bz2 4091 BLAKE2B 0fea3488a39d2b00627084f6b192dfbd7ed49bdceabbb1141d1a849ba053f786e31115e00365679b1b6fb5b0ccdf5dc0dc0803057cbffbcf0ae3d75ae9830d94 SHA512 de6c9b693bdd719d06605b5da730ee5d9cf9a1d88d58194a0ba48bd378a951c66723f561e39181222d28abb38e974a2921e14ea1f40156caf7b903778cf65790
+DIST rust-patches-1.90.0_p1.tar.bz2 6095 BLAKE2B d94899021a2ad0bd2de00c15a04b6a5437fa156f7a1b0b18d31e9487312004dfb2d9cb487eacd30592066ef168e088608bd4fc0c7e383c2fe5ec0a8bfd666b0b SHA512 351ea7dcdea3767b7affe40dc3d2684b7fc56cd0dcd06a6feb86ecb5d62d0451083fae20f878eb1a04c0f8cb31c6f7c96cb5bc84fc22844328fbcfcdf0ae03fb
+DIST rust-patches-1.91.0.tar.bz2 6041 BLAKE2B 7ebc846e0ae7b496b4ed89a8b0a5c397923e4dd6c83a1289e0b98f57477feea35978224b9c4ae19a129282a8c53bdd68f8ab615821f62e4bb5fda8e39b03eeb9 SHA512 fee179ec4e4c90aacfc7f8de2b4d41c80472e1fee17dbfc5ebf384d0fb8ec5afb3f8110a429abaf5a74a924fd1926ab69b29d1b2bafd3b5014b2ad360ca24cce
+DIST rust-patches-1.92.0_p1.tar.bz2 5993 BLAKE2B aa3183a46834b9442fd79fcda61a308b6b1831c9eab6c5a48c6fca7eef49267af815a3d53c0f17563483dbb58e4c4cb9ab09e4f00c32c37b5411d184e222079b SHA512 c2ec50796e8037b1bb1074c516816c9edc815db503ccac0cde4884a7f190e186897cb91ecbad7e1bb7e34b6753d2ccbbc59e83c8efdff452c1ed446850347000
+DIST rust-patches-1.93.0.tar.bz2 3175 BLAKE2B 4849208072cf0a047a9fe2ee27d384349b713149b7d087a6ff39a41ec1a7b77884710374dcac44c4378b320da0b4061fa531edd8b2b1cc04199fd51cdb1c2e78 SHA512 b818e14653a66447a221f84363cad54ee893842025c2b6c02c08df76bdf8666664564a5bc405ee988223048c2b986ea818d685babfddee5ff7559f9567bb9dbb
+DIST rust-patches-1.93.1.tar.bz2 3186 BLAKE2B 6ff137eb2c1b43857922ac3d9b0cc3dbe71180c05d318c5b0f54c371117426ad8daa8ec19cffc19c2550564ac4b7cfd38f4c0fa42a5b8d2ae94fe668a94aa567 SHA512 ded2af5cc9516d8bbce675f323747a96fea814f2344065a45ca7968a21e31aaa5e0bf0a45f6f831a9d62047e782306d5319c6c3ed887e3ceb75011d1849a5303
+DIST rust-patches-1.94.0.tar.bz2 3165 BLAKE2B 07187fcc95458cf3323490a54d648209ae24c9c44522f5c0bf2b12ac469e86dd1145d70557c7c09a097019b262f557af162fc3687bfda10451e2e164a0f4ec78 SHA512 39f9288335c62b477465c44904e922f1ce8b62c840a9b6ce2d13dee670f6935cfbccc88faf314d5e766103ada969513badee251b6485e8abaeadca7b65cf9e23
+DIST rust-patches-1.94.1.tar.bz2 3152 BLAKE2B 211eb9785b231225f02673967b05cb0f1ff62aee429b5950d664088b6ca7fb7c9f7067e0652db5162a7440b1422b58419363644e6f871c75253ca4529c83c2f1 SHA512 da8c7ec860a5e4d093a2abf8933a0836bf00a4b93bd505f6726a90d11d97062365055baca34bd44ca62196521468f6400625ff4c5dfabff0959f05e3bbf614e7
+DIST rust-patches-1.95.0.tar.bz2 2972 BLAKE2B f826baad880a245f9baa9c7ba4a2a7c70fe3d594c8ffb94e58633e5f4149e96a07ce561562cd3d9b303507d7299e535e7031165c108b53a962f8b848682e0c96 SHA512 0fb6662f20490b5fb0512bc670a98fa7d661476de2387fa8025edfbb8359fcef11c7e917e46750ea92231fb49a91b0228fbbe94dbf0427e7a5a924498328f3ce
+DIST rustc-1.74.1-src.tar.xz 155968724 BLAKE2B e05f2379ac94b286f85791a138e1928e5b5b5a7749f0981d82c40c2a12860f55bf96bb2f0e924e35a0f8b2447b13052d38adea909aaa3199105787bb5a4861b3 SHA512 14c7e7ed2f38ab60299d8c7d41d78f042b6b57ef822d577b5138e60bdde31cf141eccd4332a25bc5da3d58eb5313d63c1448b5dfe9e11b8055bb8ea133a9038d
+DIST rustc-1.74.1-src.tar.xz.asc 801 BLAKE2B ddf73175b164233babf31ca3a381b03e20c0f36d017c1d5f85d6ab11f0986d861ab23b11c061e6b2444ced70c3d6a494cc3de4ec86f0deb221a805491bd75420 SHA512 9a96ff9ba9a4e2af4e267b2ec126fc0675c78d0eb767703daa2f28491c3d85c2ab00fbd8584390bf658812ec6c4ab6c57e43b386db59fd505bd3134a8873a09e
+DIST rustc-1.75.0-src.tar.xz 159624388 BLAKE2B 8937b80585eddaa3e1f1ef948899d14a170308518c6fef9fe569560cdd870053776956743f796055f2119399b9ca6c0df12fedd789ae46324d071e5126c4e495 SHA512 7b0f25d91b1b5c317980fc88e059200bd43b56a70b445fbc72fb9b96e09775bfd3a98e9bd9d662af80f0ce3aef527c777ee82777e96ca876f47a972d63da8606
+DIST rustc-1.75.0-src.tar.xz.asc 801 BLAKE2B 434da96b1dc93a5aeed07f4961b087fdd15870e407283ecc00df08dbc1e9f6c65fe459b3a25d39ee55900d53ee583207098ecf3d63f5d6ea114ef0b8398b6a63 SHA512 a0e948553af77ca6e2daa82c69d79079ef7d4ec61957bdff99efd73748200d6c7caa9282daeb3fe3ef849d81a48e66a25336df4c7b6f62f975266aa8b9b93d3a
+DIST rustc-1.76.0-src.tar.xz 162267908 BLAKE2B 0cf726841a837d9906d82a6216e65edad1e3e4a798ccd1ca3824c2098d0c45473854b8bf183c6e9ca70ba095752e77c4f5ef575d98c07243d609857214175f5e SHA512 92e16cfdeb91bde341fe6c2774d92868275b07aa1d46d870ddc9291eadfe4ea9af93e06586fa7d6b8d60534903945cbbe706d354c90272712989c58d2bf174bf
+DIST rustc-1.76.0-src.tar.xz.asc 801 BLAKE2B eadb2f54fceb9c1ac60af72407a2957e37e1ba134a696675a1e9dcf23a2958b41d7f5aa1f75156e4843cefc387cdc9c909e364c3bfcabecc6bfbe262d9c6e8af SHA512 d35c010a5a129580746bcec5c0dad1b0bc1b7864a69505c7c0ccfad436fdfbdf33f87518965a09de187d6a70fb8867dc6a20037c648861031a17501577855120
+DIST rustc-1.77.1-src.tar.xz 162796048 BLAKE2B 18a9fd095808ba78bf50ec94f7fd4087a1033ec79750aa593bacf64219c77ef90c030d41a7d8bc43f7ec8eb30b316c225024be4aeb517100ff6723487f8bb282 SHA512 e057ae638e4c3e54fdb367d48f4b85458121cee0d0ee1ed72f346940b8acad2f16cd9cc8abc16fcf4a17bf244b3300bb56a7e7be3bd0c23b034692c983b84fe8
+DIST rustc-1.77.1-src.tar.xz.asc 801 BLAKE2B 175a551abdb970295d37a0797cf262ac43055a3cb75b23845dbb8696d04b7705b7a2908b82fcbce7cd7dec2e05c382d06622013b9d4aa19fab7f651f7e00bb73 SHA512 eb24976ae97d2980d4c547bcf27d815f4b98b8aa45441a7201a849ee37e0ef15671732c9916d33964b8e802a87ede758daaadf84901bd569527c8b6c48efff23
+DIST rustc-1.78.0-src.tar.xz 159181212 BLAKE2B dedae58e413689de258f852c988a9a91d4cf14c9525f2619ca6155006ddc9b2262c8141ff995e4fc6ecceec383470e50d2fa0952d933db9b3957ce5c5b96f62e SHA512 d2fb9881e28849d871fda71b1b51652be3839b3283f0d32163f258c5c707a9fb7b589da8dc03bca2fefee1abdd2b44a5f17e85d8c6df7bea119d1e8d22371941
+DIST rustc-1.78.0-src.tar.xz.asc 801 BLAKE2B a40b0eab4e9263694e79f21d92652402579f4a0587fa48b4043211bc645d4303f9af7629e9c8361938748163e99fa7cd04108156780f23f9c8600361785e834b SHA512 ef16c9eed79f36576517e9dd77b56aa767ae9dc745f5df1839e24b76084ac791b27926f3d608b41695ae6022aa10cbdd3650cad163f35037c60d3bd0427b3cbd
+DIST rustc-1.79.0-src.tar.xz 162359512 BLAKE2B 753c0e9c537644d1a12b4d38024c22952a19513791c3da6f955690c544e58964bacbdb579f94cd05910697fc31f77ed6553e5ad3b111bbdfebeea8d2a4fa19f5 SHA512 99d7f276292e5c270648473ff73e9888413a3325ef3a4d7a45f8ce77a42ac87996905f1d875888ce084b621f642017bc9e31a00da1439108dbe19b85d0eab085
+DIST rustc-1.79.0-src.tar.xz.asc 801 BLAKE2B 860283021f513f5d4c81ea1f8d9567f0a052cc53a1d51d7fd9a804a39b855e24e06ea4c73db53176c1cf846910147de6bbc26da35755f3d0d4b296503e691e64 SHA512 51eec85d71817fe21073502c1d18e44ce694dc11b1c181e82462b529a24a610c8e215e6f2640e8b6d80f028207a360e43354cafa863f49a12c547b4c5f52d7e7
+DIST rustc-1.80.1-src.tar.xz 199234944 BLAKE2B 39891362f2a4bc249f5d943e3ded48d2add9cd9c0ee3c085d7fbefbfbc784f1e029308d9486cd35a6c03b77243077dc1196c75980faeea0d4319cee057509b6a SHA512 3c746108a86eeb734c1a8c8f63ba1a45e2cb03a8cb553395a167d07dc3ce5d8d9ea365ddd95533b6952d915069b86cad7ad218d27861e0889f8e878136bd32ab
+DIST rustc-1.80.1-src.tar.xz.asc 801 BLAKE2B 0fb361678e4b580c89ccc35fd1b29d24ab41af854e5a34d24192671c93140b7d2c91e740a51f1eaa6854d5970bb91a0510aac9cb6cbf2883e77a2b941d65b010 SHA512 9d5731db73b8a982b956cb2c4736c0fc7dedab785d9855508e6a1fc2d2163d561fdcd5b254ea5f7b1f27b3903d10d9d2403366e63f9c690ab722c401109a7c1d
+DIST rustc-1.81.0-src.tar.xz 216743872 BLAKE2B d9f52da9092d0723c862ebbb2dc351cad0670be6872f691b4c9f36faf06803f072720ebd04f06745c355d807991b38312cc830b12d6d3f50b0574bb7325340b7 SHA512 b8a837ced521d2ca2c7f228a0640da591384519e4dbc1ae768524d50616da6abbd2f7bdae3777caebc0447dac91bf76481282ce5a2264d7f30e173caa6321a51
+DIST rustc-1.81.0-src.tar.xz.asc 801 BLAKE2B 01cd9f386d3fd73f4eb43b14d7d479ebababb8640abbff170e697817b94b8a18edd801c6047ecf3c084a0a51764c5e4f3f4bd6b00e8ae000ef0b850e9506572a SHA512 19c0da9d67f2bd9fd79a2078f0f486ee7fad5646a09a609b7e30d9531851955ae8df0ec69f9ddc09e2fd6e74d529648335b0fda833839c88c54c84494ec1988e
+DIST rustc-1.82.0-src.tar.xz 219769328 BLAKE2B 611f33e134c2d459c9af1695c0a4d033df93afc986e91a17fceb0dd293fb4ffbd5f7475ef571d36cecf49da6c3fdb3801c98d7f72f9dd1c39e42502f649b192f SHA512 d158c7c71c1814bde2a3ec3cbeabe34949bd3201b730c0d7ec6baad4158bb28dd13696c430a6b99dc38b9d23ad7ddf8dde7d2487cbfbbbe9c3473016994210f0
+DIST rustc-1.82.0-src.tar.xz.asc 801 BLAKE2B 8138fb15b8d7ec15be45378fe663207a8e87e3c527348ab079995b1840a771ed6e9d5464eb8855ac9e006c0cfcf54b1a4fea489d31e6c9899cb03e6f4c737b67 SHA512 3cd6b27e72041baf9996efa10f25aca2e04f3e3727b60ecfd90c1bef9c52d216d2dc130802f935b110e35766645a27637a01661aa8d5acf02bf64b02a107c93c
+DIST rustc-1.83.0-src.tar.xz 353808388 BLAKE2B 217c85f7351a7c57a2684da2c7c81a32094187b3812dee628b327a5b2faca57235abc54d033c586c071c8bfa0c7360bb28761aaa42fe18414e388db704d81231 SHA512 64db57949c6ac1df6a3f4c6bd0938685a5fb1bc3d318b34ccfcfccb0f9eff1cffd4d8a53a190ef0409eeca9ad12bc6234c2c1de69196cc74ae02d6afa20d0ce6
+DIST rustc-1.83.0-src.tar.xz.asc 801 BLAKE2B 3bacb43d50ebba579dc2d4f1726298a7887e303e15f039ef72b840e30d90bc2cf9cdbe4617a9ee113a2b1a48f1982e72cf30323d72cdfb9a65b5b4d734ca0024 SHA512 84b252ccaddc06cb05858ff64f582dd25823818c81b1e3a00362deeda06f09e6c36948fd316d5f0ca5e24949e6f99bb14a14dbd2af1cfbb85e679e27ab0a813c
+DIST rustc-1.84.0-src.tar.xz 354993944 BLAKE2B e4697d8a9f42484556ed490390aef535b2214ccb3715ade57936211c1c637737da5f2b9a6c53a30df0fba1744fbd80d4d1382c0b74f6b36b36098bf187557201 SHA512 9e964c1b964e74083a9002fa04b072fa8fe7a520b24ad55e88a89bb2a2a2cd5727c5438d6db425b824ae7502ab215c2dd3f49777efd65f76bae09965df2e070a
+DIST rustc-1.84.0-src.tar.xz.asc 801 BLAKE2B b1846702f36b92c479499f5eb704ce1e272131fc1b6b625c8d64c873a82ed79b1de8cceb1f21ae4b9dccf81e258547debf367b7b769ac94ed10a59dee18f79f1 SHA512 5ada0e0fed9901044eaa0d7cb657f685c7e183e91245714abe4a0a8bf3062a7de281932c7de7587220df0542511f6011d057bd8bed19d98c755eab74091cdfdb
+DIST rustc-1.84.1-src.tar.xz 355078168 BLAKE2B 849e8c909493bf76ce9749b9dcb1967180223b91a41d690bc477e78557d4e24949c9a8d8276d824af8c54ad62bc4a998e7a8efbc0bbd2008a4f64f51a7690d48 SHA512 f1cc4765736551508408126e44086988e8ddc30c1a929bf7b61c6be85ad0d65928dd5fb1041cfaeee8eb37d2208f2c1917e276aef2bc9a8e40e34f6713b349e1
+DIST rustc-1.84.1-src.tar.xz.asc 801 BLAKE2B f3decd3470fd1eff33adbb376490a30eb8db28dd4176bde0fefe4f60acf79c3dd0e1a330d519b5319360136ea7d0a124f6720dea08617202d9e9298da992ccf6 SHA512 a241fe3efba293f3e872b74f09dd0d184e0239afd1416326d57bf1134d92721c65b187f5c99962b51671877a539f18e82d2d797c76af42615c11a8bb3905f796
+DIST rustc-1.85.0-src.tar.xz 274011696 BLAKE2B 9cb1c5b9fa9b0ee8a3150d634b58f4d14c38342f19cffbdcaa4e783150f9b3c516763d549d9998d90e11377cd59e9d9442a99079aafccdc005739b075574447a SHA512 3e9c933d1d9b6e5fb081837cf07eb1638b1a6b4fd1cb607dd860c5021ba7b521edbaf8ba0fa8f182f62178b72a3e1a3e6b26675e8fb6530871137852a074443c
+DIST rustc-1.85.0-src.tar.xz.asc 801 BLAKE2B 8168c984f69356898f7a51199f3250a51c58a6512463cd5011acdff8c63754ba196bb050dba95b73d37c7e6d4bbcd3d1cb471d067a6615cd81b8969394e3539a SHA512 b96fffde7eb3d98cca6abe44e671fd4752416357ab3180d2a09a60fc022ac03d10e64ae285ef6276b8d881d6154fd7398f46666f5a2ea6f3023ea38fd543f59e
+DIST rustc-1.85.1-src.tar.xz 274028992 BLAKE2B 1dddbbc0d14fe9551fd2eb59a47521ac7eaf783b8ebf5e89d3e82b38f3f1539c14626a86b6530a47e5a967d47a04db7a3daef568eb5164f42d98b6826346cffe SHA512 d61afb4f00d0c63eef132e10ca5369202064ecad8ab5bcf4fbd62e9a20b2bd71840b2a769dadcf43452fc0448865975c9de1c129752caa9928d2757027bacf7c
+DIST rustc-1.85.1-src.tar.xz.asc 801 BLAKE2B 07409ef6c044b72394a28dfd5b5decb237ca540714010a4f81e4213a3bf7ffb2e14029789f930cea0dab115a6e986859f6cdefd3798be780c2ff21c3e5fa6593 SHA512 7f19653fd05c89390a4073f5184ca162863b7116cc4d8867a5aa4304568880707ebb9f9dda166d7d04f30b2df6ed223eedd98df1744f809773054edfcd2385ff
+DIST rustc-1.86.0-src.tar.xz 275696736 BLAKE2B 9f33a710a3e567d92f56091920643f5ef2ddf2ad52acb5d9ee78496a7b5dbc10da5a51c72cf2a6f66d543a531d3138a49767c98501ae4e885e03988d2ccfbb59 SHA512 9ce195e24a03765f7163de16271e3d19d731d4b80fcc2bfd919106c9d42543eade018f712f6947ea3c6e57c6cb2e6841596aa668d608b8da15101a7da14f3097
+DIST rustc-1.86.0-src.tar.xz.asc 801 BLAKE2B 3e10a3894c7eee68d37bc5707d797548119f830667e27e652a199d13633199713bd01bd0f41a5f2af3c682561903e36abe27b36ef78d9a1d65bdf485527d2c15 SHA512 0b74dab9ee56d0a08e26e9cd40f722e4d99de63ac678f969f0c54d50737074fb28e170db5a36ce2627ec332e5ce3bb8a92167aefbccff7c70e4cb057bc0a94ac
+DIST rustc-1.87.0-src.tar.xz 283604208 BLAKE2B 7ede723121ff8df3908674631ceaec75797d91ccd6f1df4afd7187878adbb8d99c9e8a3b11c6027703b2e8d06785299d93d8649f3eda7f356dd2a6734d99d05b SHA512 2ef08c9be45434401f916d54b3739f52d255f8a3a4ce05a717499250c2333eeaf601f1d18085b878c027c609f44da74d0151f5bfc2c9ae1e01166919a91a1d2b
+DIST rustc-1.87.0-src.tar.xz.asc 801 BLAKE2B c9740c03baedcd70defba3fd37831692adaf0e984ef6b11d259244330d044fcacf935e6dd76caf126848da0c40f38e5368c60e8aabed5d3c2655a61fdbdc7564 SHA512 ebc13374381839a997c63455b733fd2a7960b4fd497f19c29be948cce8bb59a31ddda5da54ca154c16f7de43dd1bacd6c6bd76f3b6b36c5b43f4cfaf1746b952
+DIST rustc-1.88.0-src.tar.xz 283294344 BLAKE2B fc17efbc8b2e54f2da61384097dcb3b8f595f27f7853f56cef034913f6b46a718113af0fe66f0e3b0afd184ec506b35f3b74172926cf727ddc061f567d54fa4c SHA512 e6c62af2953f49462b2369e9551b12f2bec114577f90e3e76049636da4279b1e7f4d53bc6896f5d0d4715d90ef6d29dacff529a45690ffac6af62ad64600db40
+DIST rustc-1.88.0-src.tar.xz.asc 801 BLAKE2B 858e987ad1fc49c1e1cbc5ea709f835c60fce907e89205e431c843bfad97dc0ccbcf399fc7d87319b8455561cbc24020bd88cb572cbe932cb8b80a8adec39687 SHA512 64ab398dc602fed3ad7bf232249e80cc0a9831aa90c7eb37658f7dc5b2af04ee391f9633aae7a1d90f743d019cec531318384f71384ecbe4f6169e6e88b7ba0e
+DIST rustc-1.89.0-src.tar.xz 267487572 BLAKE2B 9f6e3c595f843c239b57f14e26685e9856cffa10189b75627fee4dc82970a9b5f2c6f42e145d1c1042d934bd4db0334014c046450f7594d621b378d951546d5d SHA512 3ac0f02baaff12c67fe35cef4d56b315134d0a043bb6103a248a2842456c74733c6e3039f079bacfb8b8ab9b7487f92d678987e588bd41276abf9bf7c2f7870b
+DIST rustc-1.89.0-src.tar.xz.asc 801 BLAKE2B cd94da916d3646048d8f90c6de658de2981d0c815a1f8da01fe58ab6ec133e47180c8b506a41e22c68b3cb77aff5bd3bfc966a71ae2b73849918096d68764386 SHA512 006b91bf41fbedf91c39b8a6e483b089f69af7e78026f2903928fed64e44ee6aa53e46fd19bae31b1576b53a80dab66bf3e53a3bf79f820066d36285d706b90c
+DIST rustc-1.90.0-src.tar.xz 272348992 BLAKE2B 82dbbe3b5fe79f623c74fb81a4c4372b14e7d765f0e9af3d76a6c4bde9899007c85c8af70dfd9facc06c37a9c8d03a4597ec87b2d053585ccbc2287332b27e70 SHA512 fb0798b4c7450754db2fcbb641202909d209c6db2d9181d7df7282217b8320dc52f5e9853de9d7bdb79177f1f920389450cab07674dea5fb5501eaab5816662a
+DIST rustc-1.90.0-src.tar.xz.asc 801 BLAKE2B 1e84c6134c4fedbbd52610c259c1bdacb45bc97e8cce7a6b5a8c92827a072c88fcf8984893a5e6aa28c2d5d82bd849bb9d38390c783cfaa503a18c99bcaabcde SHA512 fc8f6dfbb4b50777ae8e499883f95b64861db0ca37119b34b3670b4adf51dd248b0b33daafee90e0f22f66b1d8bd8ae6a6107106e95e73f5c2c5a8dc29532e2e
+DIST rustc-1.91.0-src.tar.xz 270987196 BLAKE2B 18ea8075c288d1c2cc8c247120ae5fa157d0144f6dc8f0e30ce48eb068b2440604733b5230fcea6fcb9aa4630de03aa4af632227c5f3e62733254ee45e2a478d SHA512 1e4c7a2435dc5bccfc63f34f5d210f7cafb0113787a4b5069d61f03528a32cd0a29ac516673cbc0eb564089f1dc5e13b962e6c3714bd0109de664c22ed340fb3
+DIST rustc-1.91.0-src.tar.xz.asc 801 BLAKE2B 11b157fafcfa9887b591ffff8b87641f62e81e44d32d5c4ae99a410179905ae64fe760d6c3a6614bd479f51457542a57b171aaa53baad73d5030e496e62f1e67 SHA512 17c99b273d7e84c54b40817448cb7f543b61a5b262d2bfb1c2d1ff108ccf010295c42ae1ae74593fdab1d6caa3cd3f6713e9966a9a5057c01cd85ae3f24a6f89
+DIST rustc-1.92.0-src.tar.xz 271887480 BLAKE2B 765e0f216dde8d375e19ca5b1cd3e051b182cc058e16a1307e82e60bac06de6919d18b6506cb14b3ff5e29c2730ef7d1c6e0d86c3bbf6b8148bbf683048eb99b SHA512 a2c0b127933595b9bc2063d7b7c88d9af512c4664b18f29d44c9a6e2c68d194b87a3071717e8f1b7c858ae940baca888e10be95cd31e0201916d0bfc312a3b15
+DIST rustc-1.92.0-src.tar.xz.asc 801 BLAKE2B 0d223a763b4a3bf0583c4c2c19b2a30dfbe48b6b06c17a764c894ec29d1d0543201a78a263df3c1314c4ad9e050009e1cacb580633f8c2a8e6b2bf35d9a87fce SHA512 7355e5d641ac6f1d27decdf24dbf4af5640ae4f3177a678f8c040aa7288e660c87ed3de33efdcf4e881691b1c13cd9b2a0b6ff3067892aaed1649a4b73b610df
+DIST rustc-1.93.0-src.tar.xz 270925104 BLAKE2B f96a05dae3494452471f6797fdc2246cc0f5e8205b2a664da72fcae25399b3729aac6d8c3e0a8ed86daaa7081ca803fb5d58c6fdcf9e1d5c5d598ef9976e1da7 SHA512 9362a4b56529ce29362e256daf382b73c73204d0e9fe5b39addf07ff66a30aa66c967e34df9021ea007c13a9f3bb6efdefca1c8e4ea1bde9aac050a9fb0c736b
+DIST rustc-1.93.0-src.tar.xz.asc 801 BLAKE2B 9c1762c0bb431da8fda0a8a47f5745998ff31434bb0b2747aa4aafc34e09c1507207eb91b7ba80f7a780b7f7258a4b8e49b5c5b06f9fa9f4cfabf72edb9cb07e SHA512 a6ea05bb6b7d3b429a1c863622c93ac4c97b25f56027f7f06f085acde26d1395f3515cc764ae3ef941d1669556a02365755b34e28ccaebe70c1ccb84c977228f
+DIST rustc-1.93.1-src.tar.xz 270888296 BLAKE2B fe5a9072161cf758221974f1f59b1a198b2c62b2317360cdb8b2516cfac8eecf40cd5e69bb186053555688a167cabae3a3227b9079c360d238b12c229ff2ddc1 SHA512 fbff2e960e20a5b4c1320bfe22aca445a5792c10f902c6eb69fc7de2a1f8965b06b0906141526a5f0fa02bcbb6b02d80865481bd62656f7b9a11fbdcf5bc9f02
+DIST rustc-1.93.1-src.tar.xz.asc 801 BLAKE2B 9e059c894770a402d5fee2a29ffdb42030d8d723a40d6312d983e53cd4fa64e97019a0ea6054dcb17ba2ead7f27db17eec2632950f13e4ef1410324afc4dcaf8 SHA512 8a290300e370b3833d2d365a451ed4708dbe1fa69fc57b73eef0b2b5d9dd4fb3d87344315aee3aea474d4071cfb535234e167f6576abf2e06ef3225c85e3c30d
+DIST rustc-1.94.0-src.tar.xz 273916448 BLAKE2B cab2e007c1a5401c653218ff0dd542d10c0d7a4fcc7bf2ee269cbbb9760bdd04c78276beddc2f6b1f4d47df96a11079087f109e248951c2a157be73ca2c3e8db SHA512 8397fa68055827363bff5a1dd228a05e4c4ca5a179d072ecc1b330a874c183529cb9346ec9c531fb3f066b7b6094fc8711d7c341a49755af7b50d63bf0ecff2b
+DIST rustc-1.94.0-src.tar.xz.asc 801 BLAKE2B d6ce44d51e59ecd22b953b391134ba470ec4ee1089031c34f7809199bd4eda3f54c5907a92f362cf5c0151d75b14360cd44d5a2556f785cbc1c3de5a0335573b SHA512 0a5b067e0e137489f49c7e445992f7a456e884d39158e4d9b5b59af41c62e5dbfe8abeaa02af33ca072b663dbc649004bc83ff18899bf1bfaed0eb90aac5f67f
+DIST rustc-1.94.1-src.tar.xz 274077388 BLAKE2B 1c8c1b3f2d32898d7bfee5daa49b2d99c2dc7c1a35773c9bd66f73d45ea87f553c596561596594da2562c5bdfbd44936c53617ab114b7144e94a7d178e859af3 SHA512 4d20f5b2df042517b14aa4d1a7e4b149b7490ac6be9977d9273f5f81b70ca110b35c554693e1c8a8e4722bdb06532d3972a88c0cb7a8081d3d1bdb23e01e1546
+DIST rustc-1.94.1-src.tar.xz.asc 801 BLAKE2B 34559398b1fd0e7ff93ecf0d6a90c371048b70f834cd376a56f30b9890d9b786085a9149546a6c031e2e07bd4a349f1f3139f0e7f8bdae2a451dee47b5a13155 SHA512 6176d98acf9367e13afaef1c90ebca555f3ad08c44504f5cf23b7963959ee01ace1e99bf56aaf4f629bfb320eaca01b1940ba1819ce523d0cf336c97a69b21b7
+DIST rustc-1.95.0-src.tar.xz 238952004 BLAKE2B 0f255678231df79c9910cf5d9efbd762d1955ad78512194e3e06b3cec327f346bc98c526d2a8468ea53f57132c9765a134fe203267c1f6696e6719db820f342a SHA512 685912ffff97063e55c85b2d15d06ba734980cef4b6e104caae1ea433958b12a8d651b757eef7b9f5b06dad3c246d819a5ee5574a26e05007ecdd378f0f041d0
+DIST rustc-1.95.0-src.tar.xz.asc 801 BLAKE2B 90871b7ef3b69d0e4ef74892e16c0efab1c7ff796f646a3ef8653408d0155d528e418f71dcafca66c0689d38a3b3fba7128b1f32f4e69b7df36d86be8114bdbe SHA512 f70ed8071eff3470d4c288b83951e05f2ced52052a2f796113eb18db2c1f4bf81796f61434c322772dda879146d63569fd545d94d17e478a9588a333159c389c
diff --git a/dev-lang/rust/metadata.xml b/dev-lang/rust/metadata.xml
new file mode 100644
index 000000000000..aea75cfc6476
--- /dev/null
+++ b/dev-lang/rust/metadata.xml
@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE pkgmetadata SYSTEM "https://docs.baldeagleos.com/dtd/metadata.dtd">
+<pkgmetadata>
+  <maintainer type="project">
+    <email>rust@gentoo.org</email>
+    <name>Rust Project</name>
+  </maintainer>
+  <use>
+    <flag name="clippy">Install clippy, Rust code linter</flag>
+    <flag name="dist">Install dist tarballs (used for bootstrapping)</flag>
+    <flag name="miri">Install miri, an interpreter for Rust's mid-level intermediate representation (requires USE=nightly, sometimes is broken)</flag>
+    <flag name="mrustc-bootstrap">Use <pkg>dev-lang/mrustc</pkg> to build the bootstrap Rust sysroot from this package's source</flag>
+    <flag name="nightly">Enable nightly (UNSTABLE) features (NOTE: it does not install nightly version, just enables features marked as nightly at time of release)</flag>
+    <flag name="parallel-compiler">Build a multi-threaded rustc (experimental, not tested by upstream)</flag>
+    <flag name="rust-analyzer">Install rust-analyzer, A Rust compiler front-end for IDEs (language server)</flag>
+    <flag name="rust-src">Install rust-src, needed by developer tools and for build-std (cross)</flag>
+    <flag name="rustfmt">Install rustfmt, Rust code formatter</flag>
+    <flag name="system-llvm">Use the system LLVM installation</flag>
+    <flag name="wasm">Build support for the wasm32-unknown-unknown target</flag>
+  </use>
+  <upstream>
+    <remote-id type="cpe">cpe:/a:rust-lang:rust</remote-id>
+  </upstream>
+  <origin>baldeagleos-repo</origin>
+</pkgmetadata>
diff --git a/dev-lang/rust/rust-1.74.1-r101.ebuild b/dev-lang/rust/rust-1.74.1-r101.ebuild
new file mode 100644
index 000000000000..544512df3603
--- /dev/null
+++ b/dev-lang/rust/rust-1.74.1-r101.ebuild
@@ -0,0 +1,1109 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 17 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER=${PVR}
+
+RUST_MAX_VER=${PV}
+RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+RUST_OPTIONAL=1
+
+MRUSTC_VERSION="0.11.2"
+MRUSTC_RUST_VERSION="1.74.0"
+
+inherit check-reqs cmake edo estack flag-o-matic llvm-r1 multiprocessing multilib multilib-build \
+	optfeature python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+	EGIT_REPO_URI="https://github.com/rust-lang/rust.git"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Language empowering everyone to build reliable and efficient software"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.74.1/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k SPIRV Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto miri mrustc-bootstrap nightly parallel-compiler rustfmt rust-analyzer rust-src +system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+	mrustc-bootstrap? (
+		~dev-lang/mrustc-${MRUSTC_VERSION}
+		dev-build/cmake
+		sys-devel/gcc:*
+	)
+	!mrustc-bootstrap? ( ${RUST_DEPEND} )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	if use mrustc-bootstrap; then
+		M=$(( 2 * ${M} ))
+	fi
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	if [[ ${MERGE_TYPE} != binary ]]; then
+		pre_build_checks
+		python-any-r1_pkg_setup
+
+		export LIBGIT2_NO_PKG_CONFIG=1 #749381
+		if tc-is-cross-compiler; then
+			use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+			local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+			use "llvm_targets_${cross_llvm_target}" || \
+				die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+		fi
+
+		if use mrustc-bootstrap; then
+			if ! tc-is-gcc; then
+				# USE="mrustc-bootstrap" reqires that the build environment use GCC
+				export CC=${CHOST}-gcc
+				export CXX=${CHOST}-g++
+				tc-is-gcc || die "tc-is-gcc failed in spite of CC=${CC}"
+			fi
+		else
+			rust_pkg_setup
+		fi
+
+		if use system-llvm; then
+			llvm-r1_pkg_setup
+
+			local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+			export LLVM_LINK_SHARED=1
+			export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+		fi
+	fi
+}
+
+src_unpack() {
+	if use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+	default
+	# We'll need to revert this after the bootstrap.
+	if use mrustc-bootstrap; then
+		pushd "${S}" 2>/dev/null || die
+		patch -p0 < "${BROOT}"/usr/share/mrustc-${MRUSTC_VERSION}/patches/rustc-${MRUSTC_RUST_VERSION}-src.patch ||
+			die "Failed to patch sources to enable bootstrap with mrustc"
+		popd 2>/dev/null || die
+	fi
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/wasm_base.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc", "rust-demangler"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer"'
+	use rust-src && tools+=',"src"'
+
+	if use mrustc-bootstrap; then
+		local rust_stage0_root="${WORKDIR}/bootstrap/rust-${PV}"
+	else
+		local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+		# in case of prefix it will be already prefixed, as --print sysroot returns full path
+		[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+	fi
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		changelog-seen = 2
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		lto = "$(usex lto fat off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use mrustc-bootstrap; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "${WORKDIR}/llvm-config"
+			_EOF_
+		elif use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+# Build a very minimal llvm that we can use for bootstrap rustc codegen
+llvm_bootstrap() {
+	# Reference ${P}/src/bootstrap/native.rs for these values
+	local llvm_cmake_opts=(
+		"-G Ninja"
+		"-DLLVM_TARGET_ARCH=${CFG_COMPILER_HOST_TRIPLE%%-*}"
+		"-DLLVM_DEFAULT_TARGET_TRIPLE=${CFG_COMPILER_HOST_TRIPLE}"
+		#;Mips;PowerPC;SystemZ;JSBackend;MSP430;Sparc;NVPTX
+		"-DLLVM_TARGETS_TO_BUILD=${BOOTSTRAP_LLVM_TARGETS:=X86;ARM;AArch64}"
+		"-DLLVM_ENABLE_ASSERTIONS=OFF"
+		"-DLLVM_INCLUDE_EXAMPLES=OFF"
+		"-DLLVM_INCLUDE_TESTS=OFF"
+		"-DLLVM_INCLUDE_DOCS=OFF"
+		"-DLLVM_INCLUDE_BENCHMARKS=OFF"
+		"-DLLVM_ENABLE_ZLIB=OFF"
+		"-DLLVM_ENABLE_TERMINFO=OFF"
+		"-DLLVM_ENABLE_LIBEDIT=OFF"
+		"-DCMAKE_CXX_COMPILER=$(tc-getCXX)"
+		"-DCMAKE_C_COMPILER=$(tc-getCC)"
+		"-DCMAKE_BUILD_TYPE=Release"
+	)
+
+	if [[ -z "${LLVM_CMAKE_OPTS_EXTRA}" ]]; then
+		llvm_cmake_opts+=( "${LLVM_CMAKE_OPTS_EXTRA}")
+	fi
+
+	elog "Building bootstrap llvm ..."
+
+	mkdir -p "${WORKDIR}/bootstrap/llvm" || die
+	pushd "${WORKDIR}/bootstrap/llvm" 2>/dev/null || die
+		edo cmake ${llvm_cmake_opts[*]} "${S}/src/llvm-project/llvm"
+		eninja || die "Failed to build bootstrap llvm"
+	popd 2>/dev/null || die
+}
+
+# High level steps:
+# Our system mrustc package has built stdlib for our current platform.
+# - Step 1: Use system-installed mrustc, (m)rust(c) stdlib, and minicargo to
+#	bootstrap a `cargo` and `rustc` (mrustc-stage0)
+# - Step 2: Use minicargo and the built `rustc` to build a working `sysroot`
+#			(includes `std`, `panic_unwind``, `test`, etc.) (mrustc-stage0)
+# - Step 3: Build build libs again (this time using `cargo` and `rustc`) (mrustc-stage1)
+# - Step 4: Build a `rustc` using those libs (mrustc-stage1)
+#  - Done so there's an optimised rustc arollvm_cmake_optsund (mrustc is bad at codegen)
+# - Step 5: Build `libstd` with this `rustc` (mrustc-stage2)
+#  - Needed to match ABIs
+# Stages:
+# - mrustc-stage0: mrustc-built cargo and rustc
+# - mrustc-stage1: rustc and sysroot built with mrustc-stage0
+# - mrustc-stage2: rustc from stage1 with sysroot built with stage0
+# See:
+# - https://github.com/thepowersgang/mrustc/blob/master/run_rustc/Makefile
+# - https://github.com/thepowersgang/mrustc/blob/master/TestRustcBootstrap.sh
+# - Upstream Windows .cmd files are also a good reference for early bootstrap
+mrustc_bootstrap() {
+	export RUSTC_BOOTSTRAP=1 # Possibly the only intended use of this variable in ::gentoo
+	# export these variables now and unset them at the end of the function so they don't leak
+	# into the rest of the build.
+	export CFG_COMPILER_HOST_TRIPLE="$(rust_abi)"
+	export CFG_RELEASE="${MRUSTC_RUST_VERSION}"	# Let's pretend we're 1.74.0
+	export CFG_RELEASE_CHANNEL="stable"
+	export CFG_VERSION="${MRUSTC_RUST_VERSION}-stable-mrustc"
+	export CFG_PREFIX="mrustc"
+	export CFG_LIBDIR_RELATIVE="lib"
+	export RUSTC_INSTALL_BINDIR="bin"
+	export REAL_LIBRARY_PATH_VAR="LD_LIBRARY_PATH"
+
+	# These flags are used in every invocation of our bootstrap `cargo`.
+	local cargo_flags="--target ${CFG_COMPILER_HOST_TRIPLE} -j $(makeopts_jobs) --release --verbose"
+
+	# for bootstrap, let's using the built-in stdlib of compiler (could be the bundled one)
+	filter-flags '-stdlib=*'
+
+	# mrustc requires gcc, so disable libcxx to avoid linker failure on w/o '-lstdc++'
+	[[ "${LLVM_USE_LIBCXX}" == "1" ]] && unset LLVM_USE_LIBCXX
+
+	local llvm_config_wrapper_cxxflags=0
+
+	if use system-llvm; then
+		export LLVM_CONFIG="$(get_llvm_prefix)/bin/llvm-config"
+
+		local llvm_config_cxxflags=$(${LLVM_CONFIG} --cxxflags)
+		elog "Checking llvm-config --cxxflags: '${llvm_config_cxxflags}'"
+		[[ "${llvm_config_cxxflags}" =~ (^|[[:space:]])-stdlib=libc\+\+([[:space:]]|$) ]] && {
+			elog "Found LLVM CXXFLAGS has \"--stdlib=libc++\""
+			llvm_config_wrapper_cxxflags=1
+		}
+	else
+		llvm_bootstrap
+		export LLVM_CONFIG="${WORKDIR}/bootstrap/llvm/bin/llvm-config"
+	fi
+
+	elog "LLVM_CONFIG before wrappers: ${LLVM_CONFIG}"
+
+	# workaround for gcc bug 122409 on musl by wrapping llvm-config
+	# to append libc++ header if has "-stdlib=libc++"
+	elog "Preparing wrapper of llvm-config (${WORKDIR}/llvm-config)"
+	cat > ${WORKDIR}/llvm-config <<-EOF || die
+	#!/bin/bash
+
+	RULES=()
+	for flag in "\$@"; do
+	    case "\${flag}" in
+	$([[ "${llvm_config_wrapper_cxxflags}" == 1 ]] && {
+		echo "        --cxxflags) RULES+=( \"-E\" \"s@(^|[[:space:]]+)(-stdlib=libc\\+\\+)(\\$|[[:space:]])@\\1-I${EPREFIX}/usr/include/c++/v1 \\2\\3@g\" ) ;;"
+	})
+	        *)
+	            ;;
+	    esac
+	done
+
+	[[ -z "\${RULES}" ]] && {
+	    ${LLVM_CONFIG} "\$@"
+	} || {
+	    ${LLVM_CONFIG} "\$@" | \\
+	        tee -a ${T}/llvm-config.0.log | \\
+	        sed "\${RULES[@]}" | \\
+	        tee -a ${T}/llvm-config.1.log
+	    exit \${PIPESTATUS[0]}
+	}
+	EOF
+	export LLVM_CONFIG="${WORKDIR}/llvm-config"
+	chmod +x ${WORKDIR}/llvm-config || die
+
+	einfo "llvm-config wrapper contents:"
+	cat "${LLVM_CONFIG}" || die
+	echo
+
+	# define the mrustc sysroot and common minicargo arguments.
+	local mrustc_sysroot="${BROOT}/usr/lib/rust/mrustc-${MRUSTC_VERSION}/lib/rustlib/${CFG_COMPILER_HOST_TRIPLE}/lib"
+	local minicargo_common_args=(
+		"-L" "${mrustc_sysroot}"
+		"-j" "$(makeopts_jobs)"
+		"--vendor-dir" "${S}/vendor"
+		"--manifest-overrides"
+		"${BROOT}/usr/share/mrustc-${MRUSTC_VERSION}/patches/rustc-${MRUSTC_RUST_VERSION}-overrides.toml"
+	)
+	# There's a very good chance that minicargo and mrustc are not in the PATH.
+	if ! command -v minicargo &> /dev/null; then
+		export PATH="${BROOT}/usr/lib/rust/mrustc-${MRUSTC_VERSION}/bin:${PATH}"
+	fi
+	# Sanity check our bootstrap compiler & stdlib.
+	elog "Sanity checking mrustc and stdlib ..."
+	edo mrustc "${S}/tests/ui/hello_world/main.rs" -L "${mrustc_sysroot}" -o "${T}"/hello -g
+	"${T}"/hello || die "Failed to run hello_world"
+	# Seems fine, let's build some tools!
+
+	# Step 1: Build a `cargo` and `rustc` using system-installed mrustc
+	# Anything we produce is going to be terribly unoptimised; mrustc does not do fantastic codegen.
+	# It's good enough to bootstrap the "real" rustc though.
+	elog "Building bootstrap cargo and rustc using mrustc and minicargo (mrustc-stage0) ..."
+	local stage0="${WORKDIR}/bootstrap/mrustc-stage0"
+	mkdir -p "${stage0}" || die
+	edo minicargo "${S}"/src/tools/cargo --output-dir "${stage0}"/cargo-build ${minicargo_common_args[*]}
+	"${stage0}"/cargo-build/cargo --version || die "Bootstrap cargo failed basic sanity check"
+	edo minicargo "${S}"/compiler/rustc --output-dir "${stage0}"/rustc-build ${minicargo_common_args[*]} \
+		--features llvm
+	"${stage0}"/rustc-build/rustc_main --version || die "Bootstrap rustc failed basic sanity check"
+	# minicargo has special-casing for `rustc` so we need to rename it.
+	mv "${stage0}"/rustc-build/rustc_main "${stage0}"/rustc-build/rustc || die "Failed to rename rustc_main to rustc"
+	# rustc wants these here
+	mkdir -p "${stage0}"/codegen-backends || die
+	mv "${stage0}"/rustc-build/librustc_codegen_llvm.* "${stage0}"/codegen-backends || die
+
+	# Step 2: use the bootstrapped rustc to build sysroot; we need to use `minicargo` for this -
+	# mrustc does not accept all of the arguments that rustc does, even with the rustc_proxy wrapper.
+	# `--script-overrides`:  If the overrides are available, build scripts (and build-deps) are not built
+	# which is good since we don't have a working compiler yet, and can't build them.
+
+	local stage0_sysroot_lib="${stage0}/lib/rustlib/${CFG_COMPILER_HOST_TRIPLE}/lib"
+	# minicargo <= 0.11.2 doesn't create this directory and silently fails, besides it's better to be explicit, right?
+	mkdir -p "${stage0_sysroot_lib}" || die "Failed to create stage0 directory"
+
+	elog "Building 'sysroot' using bootstrap rustc (mrustc-stage0) ..."
+	edo env MRUSTC_PATH="${stage0}/rustc-build/rustc" minicargo -j $(makeopts_jobs) --vendor-dir "${S}"/vendor \
+		--script-overrides  "${BROOT}/usr/share/mrustc-0.11.2/script-overrides/stable-${MRUSTC_RUST_VERSION}-linux/" \
+		--output-dir "${stage0_sysroot_lib}" "${S}"/library/sysroot ||
+			die "Failed to build sysroot with bootstrap rust (mrustc-stage0)"
+
+	elog "Sanity checking sysroot and rustc ..."
+	mkdir -p "${T}"/stage0-hello || die
+	edo "${stage0}"/rustc-build/rustc -L "${stage0_sysroot_lib}" -g "${S}/tests/ui/hello_world/main.rs" \
+		-o "${T}"/stage0-hello/hello
+	"${T}"/stage0-hello/hello || die "Failed to run hello_world built with bootstrap rust stage0"
+
+	elog "mrustc bootstrap stage0 complete!"
+
+	# Step 3: Build a "proper" libstd, including dynamic libs using our bootstrap cargo and rustc.
+	elog "Building 'sysroot' with the stage0 rustc (mrustc-stage1) ..."
+	local stage1="${WORKDIR}/bootstrap/mrustc-stage1"
+	local stage1_sysroot_lib="${stage1}/lib/rustlib/${CFG_COMPILER_HOST_TRIPLE}/lib"
+	mkdir -p "${stage1_sysroot_lib}" || die "Failed to create stage1 directory"
+	mkdir -p "${stage1}/bin" || die
+
+	# Simplified to avoid calling rustc_proxy; We don't need stage1 rustc until after this is built...
+	edo env RUSTFLAGS="-Z force-unstable-if-unmarked" CARGO_TARGET_DIR="${stage1}/sysroot-build" \
+		RUSTC="${stage0}/rustc-build/rustc" "${stage0}"/cargo-build/cargo build ${cargo_flags} \
+		--manifest-path "${S}/library/sysroot/Cargo.toml" --features panic-unwind
+
+	# Move the built libs into the sysroot libdir.
+	mv "${stage1}/sysroot-build/${CFG_COMPILER_HOST_TRIPLE}/release/deps"/*.{rlib,rmeta,so} \
+		"${stage1_sysroot_lib}" || die "Failed to move stage1 libs to stage1 sysroot"
+
+	# We need to copy the stage0 rustc to the stage1 sysroot; this "updates" the sysroot location and enables
+	# resolution of stage1 libs. (run `rustc --print sysroot` on stage0 and stage1 rustc to verify)
+	cp "${stage0}/rustc-build/rustc" "${stage1}/bin/rustc" || die "Failed to copy rustc to stage1 sysroot"
+
+	# Step 4: Build `rustc` with itself, so we have a rustc with the right ABI.
+	# This will be our final `rustc` for the bootstrap process.
+	elog "Building rustc with stage1 libs (mrustc-stage1) ..."
+	mkdir -p "${stage1}/rustc-build" || die
+	edo env RUSTFLAGS="-Z force-unstable-if-unmarked -C link_args=-Wl,-rpath,\$ORIGIN/../lib" \
+		LD_LIBRARY_PATH="${stage2_sysroot_lib}" CARGO_TARGET_DIR="${stage1}/rustc-build" \
+		RUSTC="${stage1}/bin/rustc" TMPDIR="${T}" "${stage0}"/cargo-build/cargo build ${cargo_flags} \
+		--manifest-path "${S}/compiler/rustc/Cargo.toml"  --features llvm
+
+	# Step 5: Build `sysroot` with this `rustc` - Needed to match ABI
+	# We need to use the previous sysroot; we could reuse that dir but it's easier to just copy it.
+	elog "Building final 'sysroot' with the final rustc (mrustc-stage2) ..."
+	local stage2="${WORKDIR}/bootstrap/mrustc-stage2"
+	local stage2_sysroot_lib="${stage2}/lib/rustlib/${CFG_COMPILER_HOST_TRIPLE}/lib"
+	mkdir -p "${stage2_sysroot_lib}" || die "Failed to create stage2 directory"
+	mkdir -p "${stage2}/bin" || die
+
+	# Copy required files from stage1 to stage2 sysroot
+	cp "${stage1}/rustc-build/${CFG_COMPILER_HOST_TRIPLE}"/release/rustc-main "${stage2}/bin/rustc_binary" ||
+		die "Failed to copy final rustc to stage2 sysroot"
+	cp "${stage1}/rustc-build/${CFG_COMPILER_HOST_TRIPLE}"/release/librustc_driver.so "${stage2}/lib" ||
+		die "Failed to copy librustc_driver to sysroot"
+	cp "${stage1}/rustc-build/${CFG_COMPILER_HOST_TRIPLE}"/release/deps/*.{rlib,so} "${stage2_sysroot_lib}" ||
+		die "Failed to copy final rustc libs to stage2 sysroot"
+	cp "${stage1_sysroot_lib}"/* "${stage2_sysroot_lib}" || die "Failed to copy stage1 so files to stage2 sysroot"
+
+	# There's a magic script used in place of rustc so that libs can be found
+	cat <<- EOF > "${stage2}/bin/rustc" || die "Failed to create rustc wrapper"
+		#!/bin/sh
+		LD_LIBRARY_PATH="${stage2}/lib:${stage2_sysroot_lib}" ${stage2}/bin/rustc_binary "\$@"
+	EOF
+	chmod +x "${stage2}/bin/rustc" || die "Failed to make rustc wrapper executable"
+
+	# Use rustc to build 'sysroot'; this is the final step in the bootstrap process.
+	# rpath probably isn't needed here, but it doesn't hurt.
+	edo env RUSTFLAGS="-Z force-unstable-if-unmarked -C link_args=-Wl,-rpath,\$ORIGIN/../lib" \
+		CARGO_TARGET_DIR="${stage2}/stdlib-build" RUSTC="${stage2}/bin/rustc" \
+		"${stage0}"/cargo-build/cargo build ${cargo_flags} --manifest-path "${S}/library/sysroot/Cargo.toml" \
+		--features panic-unwind
+
+	# Build our final output sysroot
+	local output="${WORKDIR}/bootstrap/rust-${PV}"
+	local output_sysroot_lib="${output}/lib/rustlib/${CFG_COMPILER_HOST_TRIPLE}/lib"
+	mkdir -p "${output_sysroot_lib}" || die "Failed to create output directory"
+	mkdir -p "${output}/bin" || die "Failed to create output directory"
+
+	# Copy our various output files into the output sysroot
+	# rustc
+	cp "${stage1}/rustc-build/${CFG_COMPILER_HOST_TRIPLE}"/release/rustc-main "${output}/bin/rustc_binary" ||
+		die "Failed to copy final rustc to output"
+	cp "${stage1}/rustc-build/${CFG_COMPILER_HOST_TRIPLE}"/release/librustc_driver.so "${output}/lib" ||
+		die "Failed to copy librustc_driver to output"
+	cp "${stage1}/rustc-build/${CFG_COMPILER_HOST_TRIPLE}"/release/deps/*.{rlib,so} "${output_sysroot_lib}" ||
+		die "Failed to copy final rustc libs to output"
+	# cargo; no need to build an optimised cargo if we're using this to build a complelety new Rust.
+	cp "${stage0}/cargo-build/cargo" "${output}/bin/cargo" || die "Failed to copy cargo to output"
+	# libs
+	mv "${stage2}/stdlib-build/${CFG_COMPILER_HOST_TRIPLE}/release/deps"/*.{rlib,rmeta,so} "${output_sysroot_lib}" ||
+		die "Failed to copy stage2 libs to output"
+	# Our trusty rustc wrapper
+	cat <<- EOF > "${output}/bin/rustc" || die "Failed to create rustc wrapper"
+		#!/bin/sh
+		LD_LIBRARY_PATH="${output}/lib:${output_sysroot_lib}" ${output}/bin/rustc_binary "\$@"
+	EOF
+	chmod +x "${output}/bin/rustc" || die "Failed to make rustc wrapper executable"
+
+	# Perform a sanity check on the final Rust.
+	mkdir -p "${T}"/output-hello || die
+	edo "${output}/bin/rustc" -L "${output_sysroot_lib}" -g "${S}/tests/ui/hello_world/main.rs" \
+		-o "${T}"/output-hello/hello
+	"${T}"/output-hello/hello || die "Failed to run hello_world built with bootstrapped Rust"
+
+	elog "Successfully bootstrapped Rust using mrustc!"
+
+	# Note: The Rust sysroot that we've produced is pretty close to what we'd expect from a normal Rust build.
+	# If someone was so inclined they could build an optimised cargo using the stage2 rustc and sysroot,
+	# and install the output directly. This is untested, as I'm sure there's more to it than that.
+	# I'm satisfied with being able to build Rust normally at this point.
+
+	# Tidy up the Rust sources; revert mrustc changes so Rust can be built normally.
+	pushd "${S}" 2>/dev/null || die
+		patch -R -p0 < "${BROOT}"/usr/share/mrustc-${MRUSTC_VERSION}/patches/rustc-${MRUSTC_RUST_VERSION}-src.patch ||
+			die "Failed to revert mrustc patches"
+	popd 2>/dev/null || die
+
+	# Tidy up any environment variables we've set in the bootstrap process.
+	unset CFG_COMPILER_HOST_TRIPLE CFG_RELEASE CFG_RELEASE_CHANNEL CFG_PREFIX CFG_VERSION
+	unset CFG_LIBDIR_RELATIVE LLVM_CONFIG REAL_LIBRARY_PATH_VAR RUSTFLAGS RUSTC_BOOTSTRAP RUSTC_INSTALL_BINDIR
+}
+
+src_compile() {
+	use mrustc-bootstrap && mrustc_bootstrap
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+		rust-demangler
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	use rust-analyzer && dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-demangler
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_preinst() {
+	# 943308 and friends; basically --keep-going can forget to unmerge old rust
+	# but the soft blocker allows us to install conflicting files.
+	# This results in duplicated .{rlib,so} files which confuses rustc and results in
+	# the need for manual intervention.
+	if has_version -b "dev-lang/rust:stable/$(ver_cut 1-2)"; then
+		# we need to find all .{rlib,so} files in the old rust lib directory
+		# and store them in an array for later use
+		readarray -d '' old_rust_libs < <(
+			find "${EROOT}/usr/lib/rust/${PV}/lib/rustlib" \
+			-type f \( -name '*.rlib' -o -name '*.so' \) -print0)
+		export old_rust_libs
+		if [[ ${#old_rust_libs[@]} -gt 0 ]]; then
+			einfo "Found old .rlib and .so files in the old rust lib directory"
+		else
+			die "Found no old .rlib and .so files but old rust version is installed. Bailing!"
+		fi
+	fi
+}
+
+pkg_postinst() {
+
+	local old_rust="dev-lang/rust:stable/$(ver_cut 1-2)"
+	if has_version -b ${old_rust}; then
+		# Be _extra_ careful here as we're removing files from the live filesystem
+		local f
+		local only_one_file=()
+		einfo "Tidying up libraries files from non-slotted \`${old_rust}\`."
+		for f in "${old_rust_libs[@]}"; do
+			[[ -f ${f} ]] || die "old_rust_libs array contains non-existent file"
+			local base_name="${f%-*}"
+			local ext="${f##*.}"
+			local matching_files=("${base_name}"-*.${ext})
+			case ${#matching_files[@]} in
+				2)
+					einfo "Removing old .${ext}: ${f}"
+					rm "${f}" || die
+					;;
+				1)
+					# Turns out fingerprints are not as unique as we'd thought, _sometimes_ they collide,
+					# so we may have already installed over the old file.
+					# We'll warn about this just in case, but it's probably fine.
+					only_one_file+=( "${matching_files[0]}" )
+					;;
+				*)
+					die "Expected one or two files matching ${base_name}-\*.rlib, but found ${#matching_files[@]}"
+					;;
+			esac
+		done
+		if [[ ${#only_one_file} -gt 0 ]]; then
+			einfo "While tidying up non-slotted rust libraries for \`${old_rust}\`,"
+			einfo "the following file(s) did not have a duplicate where one was expected:"
+			for f in "${only_one_file[@]}"; do
+				einfo "	* ${f}"
+			done
+			einfo ""
+			einfo "This is unlikely to cause problems; the fingerprint for the library ended up being the same."
+			einfo "However, if you encounter any issues please report them to the Gentoo Rust Team."
+		fi
+	fi
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	optfeature "Emacs support" "app-emacs/rust-mode"
+	optfeature "Vim support" "app-vim/rust-vim"
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.75.0-r101.ebuild b/dev-lang/rust/rust-1.75.0-r101.ebuild
new file mode 100644
index 000000000000..67b6d8372c26
--- /dev/null
+++ b/dev-lang/rust/rust-1.75.0-r101.ebuild
@@ -0,0 +1,773 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 17 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER=${PVR}
+
+RUST_MAX_VER=${PV}
+RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing multilib multilib-build \
+	optfeature python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+	EGIT_REPO_URI="https://github.com/rust-lang/rust.git"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Language empowering everyone to build reliable and efficient software"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.75.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k SPIRV Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src +system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+src_unpack() {
+	if use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc", "rust-demangler"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		changelog-seen = 2
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		lto = "$(usex lto fat off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+		rust-demangler
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	use rust-analyzer && dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-demangler
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_preinst() {
+	# 943308 and friends; basically --keep-going can forget to unmerge old rust
+	# but the soft blocker allows us to install conflicting files.
+	# This results in duplicated .{rlib,so} files which confuses rustc and results in
+	# the need for manual intervention.
+	if has_version -b "dev-lang/rust:stable/$(ver_cut 1-2)"; then
+		# we need to find all .{rlib,so} files in the old rust lib directory
+		# and store them in an array for later use
+		readarray -d '' old_rust_libs < <(
+			find "${EROOT}/usr/lib/rust/${PV}/lib/rustlib" \
+			-type f \( -name '*.rlib' -o -name '*.so' \) -print0)
+		export old_rust_libs
+		if [[ ${#old_rust_libs[@]} -gt 0 ]]; then
+			einfo "Found old .rlib and .so files in the old rust lib directory"
+		else
+			die "Found no old .rlib and .so files but old rust version is installed. Bailing!"
+		fi
+	fi
+}
+
+pkg_postinst() {
+
+	local old_rust="dev-lang/rust:stable/$(ver_cut 1-2)"
+	if has_version -b ${old_rust}; then
+		# Be _extra_ careful here as we're removing files from the live filesystem
+		local f
+		local only_one_file=()
+		einfo "Tidying up libraries files from non-slotted \`${old_rust}\`."
+		for f in "${old_rust_libs[@]}"; do
+			[[ -f ${f} ]] || die "old_rust_libs array contains non-existent file"
+			local base_name="${f%-*}"
+			local ext="${f##*.}"
+			local matching_files=("${base_name}"-*.${ext})
+			case ${#matching_files[@]} in
+				2)
+					einfo "Removing old .${ext}: ${f}"
+					rm "${f}" || die
+					;;
+				1)
+					# Turns out fingerprints are not as unique as we'd thought, _sometimes_ they collide,
+					# so we may have already installed over the old file.
+					# We'll warn about this just in case, but it's probably fine.
+					only_one_file+=( "${matching_files[0]}" )
+					;;
+				*)
+					die "Expected one or two files matching ${base_name}-\*.rlib, but found ${#matching_files[@]}"
+					;;
+			esac
+		done
+		if [[ ${#only_one_file} -gt 0 ]]; then
+			einfo "While tidying up non-slotted rust libraries for \`${old_rust}\`,"
+			einfo "the following file(s) did not have a duplicate where one was expected:"
+			for f in "${only_one_file[@]}"; do
+				einfo "	* ${f}"
+			done
+			einfo ""
+			einfo "This is unlikely to cause problems; the fingerprint for the library ended up being the same."
+			einfo "However, if you encounter any issues please report them to the Gentoo Rust Team."
+		fi
+	fi
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	optfeature "Emacs support" "app-emacs/rust-mode"
+	optfeature "Vim support" "app-vim/rust-vim"
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.76.0-r101.ebuild b/dev-lang/rust/rust-1.76.0-r101.ebuild
new file mode 100644
index 000000000000..018e34473fb4
--- /dev/null
+++ b/dev-lang/rust/rust-1.76.0-r101.ebuild
@@ -0,0 +1,690 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 17 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER=${PVR}
+
+RUST_MAX_VER=${PV}
+RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing multilib multilib-build \
+	optfeature python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+	EGIT_REPO_URI="https://github.com/rust-lang/rust.git"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.76.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k SPIRV Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src +system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+src_unpack() {
+	if use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc", "rust-demangler"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		changelog-seen = 2
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+		rust-demangler
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	use rust-analyzer && dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-demangler
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_preinst() {
+	# 943308 and friends; basically --keep-going can forget to unmerge old rust
+	# but the soft blocker allows us to install conflicting files.
+	# This results in duplicated .{rlib,so} files which confuses rustc and results in
+	# the need for manual intervention.
+	if has_version -b "dev-lang/rust:stable/$(ver_cut 1-2)"; then
+		# we need to find all .{rlib,so} files in the old rust lib directory
+		# and store them in an array for later use
+		readarray -d '' old_rust_libs < <(
+			find "${EROOT}/usr/lib/rust/${PV}/lib/rustlib" \
+			-type f \( -name '*.rlib' -o -name '*.so' \) -print0)
+		export old_rust_libs
+		if [[ ${#old_rust_libs[@]} -gt 0 ]]; then
+			einfo "Found old .rlib and .so files in the old rust lib directory"
+		else
+			die "Found no old .rlib and .so files but old rust version is installed. Bailing!"
+		fi
+	fi
+}
+
+pkg_postinst() {
+
+	local old_rust="dev-lang/rust:stable/$(ver_cut 1-2)"
+	if has_version -b ${old_rust}; then
+		# Be _extra_ careful here as we're removing files from the live filesystem
+		local f
+		local only_one_file=()
+		einfo "Tidying up libraries files from non-slotted \`${old_rust}\`."
+		for f in "${old_rust_libs[@]}"; do
+			[[ -f ${f} ]] || die "old_rust_libs array contains non-existent file"
+			local base_name="${f%-*}"
+			local ext="${f##*.}"
+			local matching_files=("${base_name}"-*.${ext})
+			case ${#matching_files[@]} in
+				2)
+					einfo "Removing old .${ext}: ${f}"
+					rm "${f}" || die
+					;;
+				1)
+					# Turns out fingerprints are not as unique as we'd thought, _sometimes_ they collide,
+					# so we may have already installed over the old file.
+					# We'll warn about this just in case, but it's probably fine.
+					only_one_file+=( "${matching_files[0]}" )
+					;;
+				*)
+					die "Expected one or two files matching ${base_name}-\*.rlib, but found ${#matching_files[@]}"
+					;;
+			esac
+		done
+		if [[ ${#only_one_file} -gt 0 ]]; then
+			einfo "While tidying up non-slotted rust libraries for \`${old_rust}\`,"
+			einfo "the following file(s) did not have a duplicate where one was expected:"
+			for f in "${only_one_file[@]}"; do
+				einfo "	* ${f}"
+			done
+			einfo ""
+			einfo "This is unlikely to cause problems; the fingerprint for the library ended up being the same."
+			einfo "However, if you encounter any issues please report them to the Gentoo Rust Team."
+		fi
+	fi
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	optfeature "Emacs support" "app-emacs/rust-mode"
+	optfeature "Vim support" "app-vim/rust-vim"
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.77.1-r101.ebuild b/dev-lang/rust/rust-1.77.1-r101.ebuild
new file mode 100644
index 000000000000..7ca867447462
--- /dev/null
+++ b/dev-lang/rust/rust-1.77.1-r101.ebuild
@@ -0,0 +1,773 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 17 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER=${PVR}
+
+RUST_MAX_VER=${PV}
+RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing multilib multilib-build \
+	optfeature python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+	EGIT_REPO_URI="https://github.com/rust-lang/rust.git"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.77.1/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k SPIRV Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src +system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+src_unpack() {
+	if use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc", "rust-demangler"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		changelog-seen = 2
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+		rust-demangler
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	use rust-analyzer && dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-demangler
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_preinst() {
+	# 943308 and friends; basically --keep-going can forget to unmerge old rust
+	# but the soft blocker allows us to install conflicting files.
+	# This results in duplicated .{rlib,so} files which confuses rustc and results in
+	# the need for manual intervention.
+	if has_version -b "dev-lang/rust:stable/$(ver_cut 1-2)"; then
+		# we need to find all .{rlib,so} files in the old rust lib directory
+		# and store them in an array for later use
+		readarray -d '' old_rust_libs < <(
+			find "${EROOT}/usr/lib/rust/${PV}/lib/rustlib" \
+			-type f \( -name '*.rlib' -o -name '*.so' \) -print0)
+		export old_rust_libs
+		if [[ ${#old_rust_libs[@]} -gt 0 ]]; then
+			einfo "Found old .rlib and .so files in the old rust lib directory"
+		else
+			die "Found no old .rlib and .so files but old rust version is installed. Bailing!"
+		fi
+	fi
+}
+
+pkg_postinst() {
+
+	local old_rust="dev-lang/rust:stable/$(ver_cut 1-2)"
+	if has_version -b ${old_rust}; then
+		# Be _extra_ careful here as we're removing files from the live filesystem
+		local f
+		local only_one_file=()
+		einfo "Tidying up libraries files from non-slotted \`${old_rust}\`."
+		for f in "${old_rust_libs[@]}"; do
+			[[ -f ${f} ]] || die "old_rust_libs array contains non-existent file"
+			local base_name="${f%-*}"
+			local ext="${f##*.}"
+			local matching_files=("${base_name}"-*.${ext})
+			case ${#matching_files[@]} in
+				2)
+					einfo "Removing old .${ext}: ${f}"
+					rm "${f}" || die
+					;;
+				1)
+					# Turns out fingerprints are not as unique as we'd thought, _sometimes_ they collide,
+					# so we may have already installed over the old file.
+					# We'll warn about this just in case, but it's probably fine.
+					only_one_file+=( "${matching_files[0]}" )
+					;;
+				*)
+					die "Expected one or two files matching ${base_name}-\*.rlib, but found ${#matching_files[@]}"
+					;;
+			esac
+		done
+		if [[ ${#only_one_file} -gt 0 ]]; then
+			einfo "While tidying up non-slotted rust libraries for \`${old_rust}\`,"
+			einfo "the following file(s) did not have a duplicate where one was expected:"
+			for f in "${only_one_file[@]}"; do
+				einfo "	* ${f}"
+			done
+			einfo ""
+			einfo "This is unlikely to cause problems; the fingerprint for the library ended up being the same."
+			einfo "However, if you encounter any issues please report them to the Gentoo Rust Team."
+		fi
+	fi
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	optfeature "Emacs support" "app-emacs/rust-mode"
+	optfeature "Vim support" "app-vim/rust-vim"
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.78.0-r101.ebuild b/dev-lang/rust/rust-1.78.0-r101.ebuild
new file mode 100644
index 000000000000..87f926833618
--- /dev/null
+++ b/dev-lang/rust/rust-1.78.0-r101.ebuild
@@ -0,0 +1,776 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 18 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER=${PVR}
+
+RUST_MAX_VER=${PV}
+RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing multilib multilib-build \
+	optfeature python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+	EGIT_REPO_URI="https://github.com/rust-lang/rust.git"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.78.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k SPIRV Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src +system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+src_unpack() {
+	if use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc", "rust-demangler"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+		rust-demangler
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	use rust-analyzer && dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-demangler
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_preinst() {
+	# 943308 and friends; basically --keep-going can forget to unmerge old rust
+	# but the soft blocker allows us to install conflicting files.
+	# This results in duplicated .{rlib,so} files which confuses rustc and results in
+	# the need for manual intervention.
+	if has_version -b "dev-lang/rust:stable/$(ver_cut 1-2)"; then
+		# we need to find all .{rlib,so} files in the old rust lib directory
+		# and store them in an array for later use
+		readarray -d '' old_rust_libs < <(
+			find "${EROOT}/usr/lib/rust/${PV}/lib/rustlib" \
+			-type f \( -name '*.rlib' -o -name '*.so' \) -print0)
+		export old_rust_libs
+		if [[ ${#old_rust_libs[@]} -gt 0 ]]; then
+			einfo "Found old .rlib and .so files in the old rust lib directory"
+		else
+			die "Found no old .rlib and .so files but old rust version is installed. Bailing!"
+		fi
+	fi
+}
+
+pkg_postinst() {
+
+	local old_rust="dev-lang/rust:stable/$(ver_cut 1-2)"
+	if has_version -b ${old_rust}; then
+		# Be _extra_ careful here as we're removing files from the live filesystem
+		local f
+		local only_one_file=()
+		einfo "Tidying up libraries files from non-slotted \`${old_rust}\`."
+		for f in "${old_rust_libs[@]}"; do
+			[[ -f ${f} ]] || die "old_rust_libs array contains non-existent file"
+			local base_name="${f%-*}"
+			local ext="${f##*.}"
+			local matching_files=("${base_name}"-*.${ext})
+			case ${#matching_files[@]} in
+				2)
+					einfo "Removing old .${ext}: ${f}"
+					rm "${f}" || die
+					;;
+				1)
+					# Turns out fingerprints are not as unique as we'd thought, _sometimes_ they collide,
+					# so we may have already installed over the old file.
+					# We'll warn about this just in case, but it's probably fine.
+					only_one_file+=( "${matching_files[0]}" )
+					;;
+				*)
+					die "Expected one or two files matching ${base_name}-\*.rlib, but found ${#matching_files[@]}"
+					;;
+			esac
+		done
+		if [[ ${#only_one_file} -gt 0 ]]; then
+			einfo "While tidying up non-slotted rust libraries for \`${old_rust}\`,"
+			einfo "the following file(s) did not have a duplicate where one was expected:"
+			for f in "${only_one_file[@]}"; do
+				einfo "	* ${f}"
+			done
+			einfo ""
+			einfo "This is unlikely to cause problems; the fingerprint for the library ended up being the same."
+			einfo "However, if you encounter any issues please report them to the Gentoo Rust Team."
+		fi
+	fi
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	optfeature "Emacs support" "app-emacs/rust-mode"
+	optfeature "Vim support" "app-vim/rust-vim"
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.79.0-r101.ebuild b/dev-lang/rust/rust-1.79.0-r101.ebuild
new file mode 100644
index 000000000000..b31c03b3a61a
--- /dev/null
+++ b/dev-lang/rust/rust-1.79.0-r101.ebuild
@@ -0,0 +1,776 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 18 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER=${PVR}
+
+RUST_MAX_VER=${PV}
+RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing multilib multilib-build \
+	optfeature python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+	EGIT_REPO_URI="https://github.com/rust-lang/rust.git"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.79.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k SPIRV Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src +system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+src_unpack() {
+	if use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc", "rust-demangler"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+		rust-demangler
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	use rust-analyzer && dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-demangler
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_preinst() {
+	# 943308 and friends; basically --keep-going can forget to unmerge old rust
+	# but the soft blocker allows us to install conflicting files.
+	# This results in duplicated .{rlib,so} files which confuses rustc and results in
+	# the need for manual intervention.
+	if has_version -b "dev-lang/rust:stable/$(ver_cut 1-2)"; then
+		# we need to find all .{rlib,so} files in the old rust lib directory
+		# and store them in an array for later use
+		readarray -d '' old_rust_libs < <(
+			find "${EROOT}/usr/lib/rust/${PV}/lib/rustlib" \
+			-type f \( -name '*.rlib' -o -name '*.so' \) -print0)
+		export old_rust_libs
+		if [[ ${#old_rust_libs[@]} -gt 0 ]]; then
+			einfo "Found old .rlib and .so files in the old rust lib directory"
+		else
+			die "Found no old .rlib and .so files but old rust version is installed. Bailing!"
+		fi
+	fi
+}
+
+pkg_postinst() {
+
+	local old_rust="dev-lang/rust:stable/$(ver_cut 1-2)"
+	if has_version -b ${old_rust}; then
+		# Be _extra_ careful here as we're removing files from the live filesystem
+		local f
+		local only_one_file=()
+		einfo "Tidying up libraries files from non-slotted \`${old_rust}\`."
+		for f in "${old_rust_libs[@]}"; do
+			[[ -f ${f} ]] || die "old_rust_libs array contains non-existent file"
+			local base_name="${f%-*}"
+			local ext="${f##*.}"
+			local matching_files=("${base_name}"-*.${ext})
+			case ${#matching_files[@]} in
+				2)
+					einfo "Removing old .${ext}: ${f}"
+					rm "${f}" || die
+					;;
+				1)
+					# Turns out fingerprints are not as unique as we'd thought, _sometimes_ they collide,
+					# so we may have already installed over the old file.
+					# We'll warn about this just in case, but it's probably fine.
+					only_one_file+=( "${matching_files[0]}" )
+					;;
+				*)
+					die "Expected one or two files matching ${base_name}-\*.rlib, but found ${#matching_files[@]}"
+					;;
+			esac
+		done
+		if [[ ${#only_one_file} -gt 0 ]]; then
+			einfo "While tidying up non-slotted rust libraries for \`${old_rust}\`,"
+			einfo "the following file(s) did not have a duplicate where one was expected:"
+			for f in "${only_one_file[@]}"; do
+				einfo "	* ${f}"
+			done
+			einfo ""
+			einfo "This is unlikely to cause problems; the fingerprint for the library ended up being the same."
+			einfo "However, if you encounter any issues please report them to the Gentoo Rust Team."
+		fi
+	fi
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	optfeature "Emacs support" "app-emacs/rust-mode"
+	optfeature "Vim support" "app-vim/rust-vim"
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.80.1-r101.ebuild b/dev-lang/rust/rust-1.80.1-r101.ebuild
new file mode 100644
index 000000000000..8bfe20300115
--- /dev/null
+++ b/dev-lang/rust/rust-1.80.1-r101.ebuild
@@ -0,0 +1,774 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 18 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER=${PVR}
+
+RUST_MAX_VER=${PV}
+RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing multilib multilib-build \
+	optfeature python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+	EGIT_REPO_URI="https://github.com/rust-lang/rust.git"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.80.1/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k SPIRV Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src +system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+src_unpack() {
+	if use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	use rust-analyzer && dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_preinst() {
+	# 943308 and friends; basically --keep-going can forget to unmerge old rust
+	# but the soft blocker allows us to install conflicting files.
+	# This results in duplicated .{rlib,so} files which confuses rustc and results in
+	# the need for manual intervention.
+	if has_version -b "dev-lang/rust:stable/$(ver_cut 1-2)"; then
+		# we need to find all .{rlib,so} files in the old rust lib directory
+		# and store them in an array for later use
+		readarray -d '' old_rust_libs < <(
+			find "${EROOT}/usr/lib/rust/${PV}/lib/rustlib" \
+			-type f \( -name '*.rlib' -o -name '*.so' \) -print0)
+		export old_rust_libs
+		if [[ ${#old_rust_libs[@]} -gt 0 ]]; then
+			einfo "Found old .rlib and .so files in the old rust lib directory"
+		else
+			die "Found no old .rlib and .so files but old rust version is installed. Bailing!"
+		fi
+	fi
+}
+
+pkg_postinst() {
+
+	local old_rust="dev-lang/rust:stable/$(ver_cut 1-2)"
+	if has_version -b ${old_rust}; then
+		# Be _extra_ careful here as we're removing files from the live filesystem
+		local f
+		local only_one_file=()
+		einfo "Tidying up libraries files from non-slotted \`${old_rust}\`."
+		for f in "${old_rust_libs[@]}"; do
+			[[ -f ${f} ]] || die "old_rust_libs array contains non-existent file"
+			local base_name="${f%-*}"
+			local ext="${f##*.}"
+			local matching_files=("${base_name}"-*.${ext})
+			case ${#matching_files[@]} in
+				2)
+					einfo "Removing old .${ext}: ${f}"
+					rm "${f}" || die
+					;;
+				1)
+					# Turns out fingerprints are not as unique as we'd thought, _sometimes_ they collide,
+					# so we may have already installed over the old file.
+					# We'll warn about this just in case, but it's probably fine.
+					only_one_file+=( "${matching_files[0]}" )
+					;;
+				*)
+					die "Expected one or two files matching ${base_name}-\*.rlib, but found ${#matching_files[@]}"
+					;;
+			esac
+		done
+		if [[ ${#only_one_file} -gt 0 ]]; then
+			einfo "While tidying up non-slotted rust libraries for \`${old_rust}\`,"
+			einfo "the following file(s) did not have a duplicate where one was expected:"
+			for f in "${only_one_file[@]}"; do
+				einfo "	* ${f}"
+			done
+			einfo ""
+			einfo "This is unlikely to cause problems; the fingerprint for the library ended up being the same."
+			einfo "However, if you encounter any issues please report them to the Gentoo Rust Team."
+		fi
+	fi
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	optfeature "Emacs support" "app-emacs/rust-mode"
+	optfeature "Vim support" "app-vim/rust-vim"
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.81.0-r101.ebuild b/dev-lang/rust/rust-1.81.0-r101.ebuild
new file mode 100644
index 000000000000..66e0c8ccff01
--- /dev/null
+++ b/dev-lang/rust/rust-1.81.0-r101.ebuild
@@ -0,0 +1,775 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 18 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER=${PVR}
+
+RUST_MAX_VER=${PV}
+RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature \
+	multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+	EGIT_REPO_URI="https://github.com/rust-lang/rust.git"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~sparc x86"
+fi
+
+RUST_STAGE0_VERSION="1.$(($(ver_cut 2) - 1)).1"
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.81.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k SPIRV Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src +system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+src_unpack() {
+	if use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	use rust-analyzer && dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_preinst() {
+	# 943308 and friends; basically --keep-going can forget to unmerge old rust
+	# but the soft blocker allows us to install conflicting files.
+	# This results in duplicated .{rlib,so} files which confuses rustc and results in
+	# the need for manual intervention.
+	if has_version -b "dev-lang/rust:stable/$(ver_cut 1-2)"; then
+		# we need to find all .{rlib,so} files in the old rust lib directory
+		# and store them in an array for later use
+		readarray -d '' old_rust_libs < <(
+			find "${EROOT}/usr/lib/rust/${PV}/lib/rustlib" \
+			-type f \( -name '*.rlib' -o -name '*.so' \) -print0)
+		export old_rust_libs
+		if [[ ${#old_rust_libs[@]} -gt 0 ]]; then
+			einfo "Found old .rlib and .so files in the old rust lib directory"
+		else
+			die "Found no old .rlib and .so files but old rust version is installed. Bailing!"
+		fi
+	fi
+}
+
+pkg_postinst() {
+
+	local old_rust="dev-lang/rust:stable/$(ver_cut 1-2)"
+	if has_version -b ${old_rust}; then
+		# Be _extra_ careful here as we're removing files from the live filesystem
+		local f
+		local only_one_file=()
+		einfo "Tidying up libraries files from non-slotted \`${old_rust}\`."
+		for f in "${old_rust_libs[@]}"; do
+			[[ -f ${f} ]] || die "old_rust_libs array contains non-existent file"
+			local base_name="${f%-*}"
+			local ext="${f##*.}"
+			local matching_files=("${base_name}"-*.${ext})
+			case ${#matching_files[@]} in
+				2)
+					einfo "Removing old .${ext}: ${f}"
+					rm "${f}" || die
+					;;
+				1)
+					# Turns out fingerprints are not as unique as we'd thought, _sometimes_ they collide,
+					# so we may have already installed over the old file.
+					# We'll warn about this just in case, but it's probably fine.
+					only_one_file+=( "${matching_files[0]}" )
+					;;
+				*)
+					die "Expected one or two files matching ${base_name}-\*.rlib, but found ${#matching_files[@]}"
+					;;
+			esac
+		done
+		if [[ ${#only_one_file} -gt 0 ]]; then
+			einfo "While tidying up non-slotted rust libraries for \`${old_rust}\`,"
+			einfo "the following file(s) did not have a duplicate where one was expected:"
+			for f in "${only_one_file[@]}"; do
+				einfo "	* ${f}"
+			done
+			einfo ""
+			einfo "This is unlikely to cause problems; the fingerprint for the library ended up being the same."
+			einfo "However, if you encounter any issues please report them to the Gentoo Rust Team."
+		fi
+	fi
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	optfeature "Emacs support" "app-emacs/rust-mode"
+	optfeature "Vim support" "app-vim/rust-vim"
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.82.0-r103.ebuild b/dev-lang/rust/rust-1.82.0-r103.ebuild
new file mode 100644
index 000000000000..fb3e947b69b1
--- /dev/null
+++ b/dev-lang/rust/rust-1.82.0-r103.ebuild
@@ -0,0 +1,778 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 19 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER=${PVR}
+
+RUST_MAX_VER=${PV}
+RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature \
+	multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+	EGIT_REPO_URI="https://github.com/rust-lang/rust.git"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.82.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k SPIRV Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src +system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+src_unpack() {
+	if use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${PV}/share/man/
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	use rust-analyzer && dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_preinst() {
+	# 943308 and friends; basically --keep-going can forget to unmerge old rust
+	# but the soft blocker allows us to install conflicting files.
+	# This results in duplicated .{rlib,so} files which confuses rustc and results in
+	# the need for manual intervention.
+	if has_version -b "dev-lang/rust:stable/$(ver_cut 1-2)"; then
+		# we need to find all .{rlib,so} files in the old rust lib directory
+		# and store them in an array for later use
+		readarray -d '' old_rust_libs < <(
+			find "${EROOT}/usr/lib/rust/${PV}/lib/rustlib" \
+			-type f \( -name '*.rlib' -o -name '*.so' \) -print0)
+		export old_rust_libs
+		if [[ ${#old_rust_libs[@]} -gt 0 ]]; then
+			einfo "Found old .rlib and .so files in the old rust lib directory"
+		else
+			die "Found no old .rlib and .so files but old rust version is installed. Bailing!"
+		fi
+	fi
+}
+
+pkg_postinst() {
+
+	local old_rust="dev-lang/rust:stable/$(ver_cut 1-2)"
+	if has_version -b ${old_rust}; then
+		# Be _extra_ careful here as we're removing files from the live filesystem
+		local f
+		local only_one_file=()
+		einfo "Tidying up libraries files from non-slotted \`${old_rust}\`."
+		for f in "${old_rust_libs[@]}"; do
+			[[ -f ${f} ]] || die "old_rust_libs array contains non-existent file"
+			local base_name="${f%-*}"
+			local ext="${f##*.}"
+			local matching_files=("${base_name}"-*.${ext})
+			case ${#matching_files[@]} in
+				2)
+					einfo "Removing old .${ext}: ${f}"
+					rm "${f}" || die
+					;;
+				1)
+					# Turns out fingerprints are not as unique as we'd thought, _sometimes_ they collide,
+					# so we may have already installed over the old file.
+					# We'll warn about this just in case, but it's probably fine.
+					only_one_file+=( "${matching_files[0]}" )
+					;;
+				*)
+					die "Expected one or two files matching ${base_name}-\*.rlib, but found ${#matching_files[@]}"
+					;;
+			esac
+		done
+		if [[ ${#only_one_file} -gt 0 ]]; then
+			einfo "While tidying up non-slotted rust libraries for \`${old_rust}\`,"
+			einfo "the following file(s) did not have a duplicate where one was expected:"
+			for f in "${only_one_file[@]}"; do
+				einfo "	* ${f}"
+			done
+			einfo ""
+			einfo "This is unlikely to cause problems; the fingerprint for the library ended up being the same."
+			einfo "However, if you encounter any issues please report them to the Gentoo Rust Team."
+		fi
+	fi
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	optfeature "Emacs support" "app-emacs/rust-mode"
+	optfeature "Vim support" "app-vim/rust-vim"
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.83.0-r3.ebuild b/dev-lang/rust/rust-1.83.0-r3.ebuild
new file mode 100644
index 000000000000..e45c475be9c2
--- /dev/null
+++ b/dev-lang/rust/rust-1.83.0-r3.ebuild
@@ -0,0 +1,760 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 19 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER=${PVR}
+
+RUST_MAX_VER=${PV}
+RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature \
+	multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+	EGIT_REPO_URI="https://github.com/rust-lang/rust.git"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.83.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k SPIRV Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src +system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+src_unpack() {
+	if use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${PV}/share/man/
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	use rust-analyzer && dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_preinst() {
+	# 943308 and friends; basically --keep-going can forget to unmerge old rust
+	# but the soft blocker allows us to install conflicting files.
+	# This results in duplicated .{rlib,so} files which confuses rustc and results in
+	# the need for manual intervention.
+	if has_version -b "dev-lang/rust:stable/$(ver_cut 1-2)"; then
+		# we need to find all .{rlib,so} files in the old rust lib directory
+		# and store them in an array for later use
+		readarray -d '' old_rust_libs < <(
+			find "${EROOT}/usr/lib/rust/${PV}/lib/rustlib" \
+			-type f \( -name '*.rlib' -o -name '*.so' \) -print0)
+		export old_rust_libs
+		if [[ ${#old_rust_libs[@]} -gt 0 ]]; then
+			einfo "Found old .rlib and .so files in the old rust lib directory"
+		else
+			die "Found no old .rlib and .so files but old rust version is installed. Bailing!"
+		fi
+	fi
+}
+
+pkg_postinst() {
+
+	if has_version -b "dev-lang/rust:stable/$(ver_cut 1-2)"; then
+		# Be _extra_ careful here as we're removing files from the live filesystem
+		local f
+		for f in "${old_rust_libs[@]}"; do
+			[[ -f ${f} ]] || die "old_rust_libs array contains non-existent file"
+			local base_name="${f%-*}"
+			local ext="${f##*.}"
+			local matching_files=("${base_name}"-*.${ext})
+			if [[ ${#matching_files[@]} -ne 2 ]]; then
+				die "Expected exactly two files matching ${base_name}-\*.rlib, but found ${#matching_files[@]}"
+			fi
+			einfo "Removing old .rlib file ${f}"
+			rm "${f}" || die
+		done
+	fi
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.84.0-r2.ebuild b/dev-lang/rust/rust-1.84.0-r2.ebuild
new file mode 100644
index 000000000000..05e79db4d6d4
--- /dev/null
+++ b/dev-lang/rust/rust-1.84.0-r2.ebuild
@@ -0,0 +1,739 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 19 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER=${PVR}
+
+RUST_MAX_VER=${PV}
+RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature \
+	multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+	EGIT_REPO_URI="https://github.com/rust-lang/rust.git"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.84.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k SPIRV Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src +system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	lto? ( system-llvm? (
+		|| (
+			$(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}')
+			sys-devel/mold
+		)
+	) )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+src_unpack() {
+	if use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	if use lto && tc-is-clang && ! tc-ld-is-lld && ! tc-ld-is-mold; then
+		export RUSTFLAGS+=" -C link-arg=-fuse-ld=lld"
+	fi
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		# https://github.com/rust-lang/rust/issues/135358 (bug #947897)
+		profile = "dist"
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		$(if use lto && tc-is-clang && ! tc-ld-is-mold; then
+			echo "use-lld = true"
+		fi)
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${PV}/share/man/
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	use rust-analyzer && dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.84.1-r2.ebuild b/dev-lang/rust/rust-1.84.1-r2.ebuild
new file mode 100644
index 000000000000..05e79db4d6d4
--- /dev/null
+++ b/dev-lang/rust/rust-1.84.1-r2.ebuild
@@ -0,0 +1,739 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 19 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER=${PVR}
+
+RUST_MAX_VER=${PV}
+RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature \
+	multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+	EGIT_REPO_URI="https://github.com/rust-lang/rust.git"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.84.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k SPIRV Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src +system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	lto? ( system-llvm? (
+		|| (
+			$(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}')
+			sys-devel/mold
+		)
+	) )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+src_unpack() {
+	if use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	if use lto && tc-is-clang && ! tc-ld-is-lld && ! tc-ld-is-mold; then
+		export RUSTFLAGS+=" -C link-arg=-fuse-ld=lld"
+	fi
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		# https://github.com/rust-lang/rust/issues/135358 (bug #947897)
+		profile = "dist"
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		$(if use lto && tc-is-clang && ! tc-ld-is-mold; then
+			echo "use-lld = true"
+		fi)
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${PV}/share/man/
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	use rust-analyzer && dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.85.0-r2.ebuild b/dev-lang/rust/rust-1.85.0-r2.ebuild
new file mode 100644
index 000000000000..8cc1b0f7999d
--- /dev/null
+++ b/dev-lang/rust/rust-1.85.0-r2.ebuild
@@ -0,0 +1,813 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 19 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER=${PVR}
+
+RUST_MAX_VER=${PV%%_*}
+if [[ ${PV} == *9999* ]]; then
+	RUST_MIN_VER="1.85.0" # Update this as new `beta` releases come out.
+elif [[ ${PV} == *beta* ]]; then
+	# Enforce that `beta` is built from `stable`.
+	# While uncommon it is possible for feature changes within `beta` to result
+	# in an older snapshot being unable to build a newer one without modifying the sources.
+	# 'stable' releases should always be able to build a beta snapshot so just use those.
+	RUST_MAX_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).1"
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+else
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+fi
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature \
+	multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+	EGIT_REPO_URI="https://github.com/rust-lang/rust.git"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language originally developed by Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.84.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k SPIRV Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV%%_*}" # Beta releases get to share the same SLOT as the eventual stable
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto rustfmt rust-analyzer rust-src +system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+if [[ ${PV} = *9999* ]]; then
+	# These USE flags require nightly rust
+	IUSE+=" miri"
+fi
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	lto? ( system-llvm? (
+		|| (
+			$(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}')
+			sys-devel/mold
+		)
+	) )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${SLOT}/bin/.*
+	usr/lib/${PN}/${SLOT}/libexec/.*
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${SLOT}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	if [[ ${PV} == *9999* ]]; then
+		M=$(( $(usex miri 128 0) + ${M} ))
+	fi
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+src_unpack() {
+	if [[ ${PV} = *9999* ]]; then
+		git-r3_src_unpack
+		mkdir "${S}/.cargo" || die # The vendor script has a check for .cargo/config{,.toml}
+		touch "${S}/.cargo/config.toml" || die
+		local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+		local rust_build=""
+		local rust_host=""
+		# Configure vendor to use the portage-provided toolchain. This prevents it from
+		# attempting to fetch a `beta` toolchain from the internet.
+		cat <<- _EOF_ > "${T}/vendor-config.toml"
+			[build]
+			build = "$(rust_abi "${CBUILD}")"
+			host = ["$(rust_abi "${CHOST}")"]
+			target = ["$(rust_abi "${CHOST}")"]
+			cargo = "${rust_stage0_root}/bin/cargo"
+			rustc = "${rust_stage0_root}/bin/rustc"
+			rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		_EOF_
+		# We're using git sources so we need to run the Vendor script
+		# to ensure that all dependencies are present and up-to-date
+		mkdir "${S}/vendor" || die
+		# This also compiles the 'build helper', there's no way to avoid this.
+		${EPYTHON} "${S}"/x.py vendor -v --config="${T}"/vendor-config.toml -j$(makeopts_jobs) ||
+			die "Failed to vendor dependencies"
+		# TODO: This has to be generated somehow, this is from a 1.84.x tarball I had lying around.
+		cat <<- _EOF_ > "${S}/.cargo/config.toml"
+			[source.crates-io]
+			replace-with = "vendored-sources"
+
+			[source."git+https://github.com/rust-lang/team"]
+			git = "https://github.com/rust-lang/team"
+			replace-with = "vendored-sources"
+
+			[source.vendored-sources]
+			directory = "vendor"
+		_EOF_
+	elif use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	if [[ ${PV} = *9999* ]]; then
+		# We need to update / generate lockfiles for the workspace
+		${CARGO} generate-lockfile --offline || die "Failed to generate lockfiles"
+	fi
+
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	if use lto && tc-is-clang && ! tc-ld-is-lld && ! tc-ld-is-mold; then
+		export RUSTFLAGS+=" -C link-arg=-fuse-ld=lld"
+	fi
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	if [[ ${PV} == *9999* ]]; then
+		use miri && tools+=',"miri"'
+	fi
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	local build_channel
+	local build_miri="false"
+	case "${PV}" in
+		*9999*)
+			build_channel="nightly"
+			;;
+		*beta*)
+			build_channel="beta"
+			;;
+		*)
+			build_channel="stable"
+			;;
+	esac
+	cat <<- _EOF_ > "${S}"/config.toml
+		# https://github.com/rust-lang/rust/issues/135358 (bug #947897)
+		profile = "dist"
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${SLOT}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		channel = "${build_channel}"
+		description = "gentoo"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		$(if use lto && tc-is-clang && ! tc-ld-is-mold; then
+			echo "use-lld = true"
+		fi)
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${SLOT}/share/man/
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${SLOT}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	if [[ ${PV} = *9999* ]]; then
+		use miri && symlinks+=( miri cargo-miri )
+	fi
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV%%_*}"
+		if [[ -f "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" "${ED}/usr/lib/${PN}/${SLOT}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${SLOT}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${SLOT}/lib" "/usr/lib/${PN}/lib-${SLOT}"
+	use rust-analyzer && dosym "${SLOT}/libexec" "/usr/lib/${PN}/libexec-${SLOT}"
+	dosym "${SLOT}/share/man" "/usr/lib/${PN}/man-${SLOT}"
+	dosym "rust/${SLOT}/lib/rustlib" "/usr/lib/rustlib-${SLOT}"
+	dosym "../../lib/${PN}/${SLOT}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${SLOT}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${PN}-${SLOT}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if [[ ${SLOT} == *9999* ]] && use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${PN}-${SLOT}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${SLOT}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.85.1-r1.ebuild b/dev-lang/rust/rust-1.85.1-r1.ebuild
new file mode 100644
index 000000000000..8cc1b0f7999d
--- /dev/null
+++ b/dev-lang/rust/rust-1.85.1-r1.ebuild
@@ -0,0 +1,813 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 19 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER=${PVR}
+
+RUST_MAX_VER=${PV%%_*}
+if [[ ${PV} == *9999* ]]; then
+	RUST_MIN_VER="1.85.0" # Update this as new `beta` releases come out.
+elif [[ ${PV} == *beta* ]]; then
+	# Enforce that `beta` is built from `stable`.
+	# While uncommon it is possible for feature changes within `beta` to result
+	# in an older snapshot being unable to build a newer one without modifying the sources.
+	# 'stable' releases should always be able to build a beta snapshot so just use those.
+	RUST_MAX_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).1"
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+else
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+fi
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature \
+	multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+	EGIT_REPO_URI="https://github.com/rust-lang/rust.git"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language originally developed by Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.84.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k SPIRV Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV%%_*}" # Beta releases get to share the same SLOT as the eventual stable
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto rustfmt rust-analyzer rust-src +system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+if [[ ${PV} = *9999* ]]; then
+	# These USE flags require nightly rust
+	IUSE+=" miri"
+fi
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	lto? ( system-llvm? (
+		|| (
+			$(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}')
+			sys-devel/mold
+		)
+	) )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${SLOT}/bin/.*
+	usr/lib/${PN}/${SLOT}/libexec/.*
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${SLOT}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	if [[ ${PV} == *9999* ]]; then
+		M=$(( $(usex miri 128 0) + ${M} ))
+	fi
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+src_unpack() {
+	if [[ ${PV} = *9999* ]]; then
+		git-r3_src_unpack
+		mkdir "${S}/.cargo" || die # The vendor script has a check for .cargo/config{,.toml}
+		touch "${S}/.cargo/config.toml" || die
+		local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+		local rust_build=""
+		local rust_host=""
+		# Configure vendor to use the portage-provided toolchain. This prevents it from
+		# attempting to fetch a `beta` toolchain from the internet.
+		cat <<- _EOF_ > "${T}/vendor-config.toml"
+			[build]
+			build = "$(rust_abi "${CBUILD}")"
+			host = ["$(rust_abi "${CHOST}")"]
+			target = ["$(rust_abi "${CHOST}")"]
+			cargo = "${rust_stage0_root}/bin/cargo"
+			rustc = "${rust_stage0_root}/bin/rustc"
+			rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		_EOF_
+		# We're using git sources so we need to run the Vendor script
+		# to ensure that all dependencies are present and up-to-date
+		mkdir "${S}/vendor" || die
+		# This also compiles the 'build helper', there's no way to avoid this.
+		${EPYTHON} "${S}"/x.py vendor -v --config="${T}"/vendor-config.toml -j$(makeopts_jobs) ||
+			die "Failed to vendor dependencies"
+		# TODO: This has to be generated somehow, this is from a 1.84.x tarball I had lying around.
+		cat <<- _EOF_ > "${S}/.cargo/config.toml"
+			[source.crates-io]
+			replace-with = "vendored-sources"
+
+			[source."git+https://github.com/rust-lang/team"]
+			git = "https://github.com/rust-lang/team"
+			replace-with = "vendored-sources"
+
+			[source.vendored-sources]
+			directory = "vendor"
+		_EOF_
+	elif use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	if [[ ${PV} = *9999* ]]; then
+		# We need to update / generate lockfiles for the workspace
+		${CARGO} generate-lockfile --offline || die "Failed to generate lockfiles"
+	fi
+
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	if use lto && tc-is-clang && ! tc-ld-is-lld && ! tc-ld-is-mold; then
+		export RUSTFLAGS+=" -C link-arg=-fuse-ld=lld"
+	fi
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	if [[ ${PV} == *9999* ]]; then
+		use miri && tools+=',"miri"'
+	fi
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	local build_channel
+	local build_miri="false"
+	case "${PV}" in
+		*9999*)
+			build_channel="nightly"
+			;;
+		*beta*)
+			build_channel="beta"
+			;;
+		*)
+			build_channel="stable"
+			;;
+	esac
+	cat <<- _EOF_ > "${S}"/config.toml
+		# https://github.com/rust-lang/rust/issues/135358 (bug #947897)
+		profile = "dist"
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${SLOT}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		channel = "${build_channel}"
+		description = "gentoo"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		$(if use lto && tc-is-clang && ! tc-ld-is-mold; then
+			echo "use-lld = true"
+		fi)
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${SLOT}/share/man/
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${SLOT}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	if [[ ${PV} = *9999* ]]; then
+		use miri && symlinks+=( miri cargo-miri )
+	fi
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV%%_*}"
+		if [[ -f "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" "${ED}/usr/lib/${PN}/${SLOT}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${SLOT}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${SLOT}/lib" "/usr/lib/${PN}/lib-${SLOT}"
+	use rust-analyzer && dosym "${SLOT}/libexec" "/usr/lib/${PN}/libexec-${SLOT}"
+	dosym "${SLOT}/share/man" "/usr/lib/${PN}/man-${SLOT}"
+	dosym "rust/${SLOT}/lib/rustlib" "/usr/lib/rustlib-${SLOT}"
+	dosym "../../lib/${PN}/${SLOT}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${SLOT}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${PN}-${SLOT}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if [[ ${SLOT} == *9999* ]] && use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${PN}-${SLOT}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${SLOT}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.86.0-r2.ebuild b/dev-lang/rust/rust-1.86.0-r2.ebuild
new file mode 100644
index 000000000000..e81e5cdac0b0
--- /dev/null
+++ b/dev-lang/rust/rust-1.86.0-r2.ebuild
@@ -0,0 +1,814 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 19 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER="${PVR}-1"
+
+RUST_MAX_VER=${PV%%_*}
+if [[ ${PV} == *9999* ]]; then
+	RUST_MIN_VER="1.85.0" # Update this as new `beta` releases come out.
+elif [[ ${PV} == *beta* ]]; then
+	# Enforce that `beta` is built from `stable`.
+	# While uncommon it is possible for feature changes within `beta` to result
+	# in an older snapshot being unable to build a newer one without modifying the sources.
+	# 'stable' releases should always be able to build a beta snapshot so just use those.
+	RUST_MAX_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).1"
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+else
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+fi
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature \
+	multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+	EGIT_REPO_URI="https://github.com/rust-lang/rust.git"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language originally developed by Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.84.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k SPIRV Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV%%_*}" # Beta releases get to share the same SLOT as the eventual stable
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto rustfmt rust-analyzer rust-src +system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+if [[ ${PV} = *9999* ]]; then
+	# These USE flags require nightly rust
+	IUSE+=" miri"
+fi
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	lto? ( system-llvm? (
+		|| (
+			$(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}')
+			sys-devel/mold
+		)
+	) )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust:1.86
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${SLOT}/bin/.*
+	usr/lib/${PN}/${SLOT}/libexec/.*
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${SLOT}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	if [[ ${PV} == *9999* ]]; then
+		M=$(( $(usex miri 128 0) + ${M} ))
+	fi
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+src_unpack() {
+	if [[ ${PV} = *9999* ]]; then
+		git-r3_src_unpack
+		mkdir "${S}/.cargo" || die # The vendor script has a check for .cargo/config{,.toml}
+		touch "${S}/.cargo/config.toml" || die
+		local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+		local rust_build=""
+		local rust_host=""
+		# Configure vendor to use the portage-provided toolchain. This prevents it from
+		# attempting to fetch a `beta` toolchain from the internet.
+		cat <<- _EOF_ > "${T}/vendor-config.toml"
+			[build]
+			build = "$(rust_abi "${CBUILD}")"
+			host = ["$(rust_abi "${CHOST}")"]
+			target = ["$(rust_abi "${CHOST}")"]
+			cargo = "${rust_stage0_root}/bin/cargo"
+			rustc = "${rust_stage0_root}/bin/rustc"
+			rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		_EOF_
+		# We're using git sources so we need to run the Vendor script
+		# to ensure that all dependencies are present and up-to-date
+		mkdir "${S}/vendor" || die
+		# This also compiles the 'build helper', there's no way to avoid this.
+		${EPYTHON} "${S}"/x.py vendor -v --config="${T}"/vendor-config.toml -j$(makeopts_jobs) ||
+			die "Failed to vendor dependencies"
+		# TODO: This has to be generated somehow, this is from a 1.84.x tarball I had lying around.
+		cat <<- _EOF_ > "${S}/.cargo/config.toml"
+			[source.crates-io]
+			replace-with = "vendored-sources"
+
+			[source."git+https://github.com/rust-lang/team"]
+			git = "https://github.com/rust-lang/team"
+			replace-with = "vendored-sources"
+
+			[source.vendored-sources]
+			directory = "vendor"
+		_EOF_
+	elif use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	if [[ ${PV} = *9999* ]]; then
+		# We need to update / generate lockfiles for the workspace
+		${CARGO} generate-lockfile --offline || die "Failed to generate lockfiles"
+	fi
+
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	if use lto && tc-is-clang && ! tc-ld-is-lld && ! tc-ld-is-mold; then
+		export RUSTFLAGS+=" -C link-arg=-fuse-ld=lld"
+	fi
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	if [[ ${PV} == *9999* ]]; then
+		use miri && tools+=',"miri"'
+	fi
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	local build_channel
+	local build_miri="false"
+	case "${PV}" in
+		*9999*)
+			build_channel="nightly"
+			;;
+		*beta*)
+			build_channel="beta"
+			;;
+		*)
+			build_channel="stable"
+			;;
+	esac
+	cat <<- _EOF_ > "${S}"/config.toml
+		# https://github.com/rust-lang/rust/issues/135358 (bug #947897)
+		profile = "dist"
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${SLOT}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		channel = "${build_channel}"
+		description = "gentoo"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		$(if use lto && tc-is-clang && ! tc-ld-is-mold; then
+			echo "use-lld = true"
+		fi)
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${SLOT}/share/man/
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${SLOT}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	if [[ ${PV} = *9999* ]]; then
+		use miri && symlinks+=( miri cargo-miri )
+	fi
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV%%_*}"
+		if [[ -f "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" "${ED}/usr/lib/${PN}/${SLOT}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${SLOT}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${SLOT}/lib" "/usr/lib/${PN}/lib-${SLOT}"
+	use rust-analyzer && dosym "${SLOT}/libexec" "/usr/lib/${PN}/libexec-${SLOT}"
+	dosym "${SLOT}/share/man" "/usr/lib/${PN}/man-${SLOT}"
+	dosym "rust/${SLOT}/lib/rustlib" "/usr/lib/rustlib-${SLOT}"
+	dosym "../../lib/${PN}/${SLOT}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${SLOT}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${PN}-${SLOT}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if [[ ${SLOT} == *9999* ]] && use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${PN}-${SLOT}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${SLOT}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.87.0-r1.ebuild b/dev-lang/rust/rust-1.87.0-r1.ebuild
new file mode 100644
index 000000000000..4f8cb5dd580f
--- /dev/null
+++ b/dev-lang/rust/rust-1.87.0-r1.ebuild
@@ -0,0 +1,821 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 20 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER="${PVR}-1"
+
+RUST_MAX_VER=${PV%%_*}
+if [[ ${PV} == *9999* ]]; then
+	RUST_MIN_VER="1.85.0" # Update this as new `beta` releases come out.
+elif [[ ${PV} == *beta* ]]; then
+	# Enforce that `beta` is built from `stable`.
+	# While uncommon it is possible for feature changes within `beta` to result
+	# in an older snapshot being unable to build a newer one without modifying the sources.
+	# 'stable' releases should always be able to build a beta snapshot so just use those.
+	RUST_MAX_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).1"
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+else
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+fi
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature \
+	multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+	EGIT_REPO_URI="https://github.com/rust-lang/rust.git"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language originally developed by Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.87.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV%%_*}" # Beta releases get to share the same SLOT as the eventual stable
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto rustfmt rust-analyzer rust-src +system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+if [[ ${PV} = *9999* ]]; then
+	# These USE flags require nightly rust
+	IUSE+=" miri"
+fi
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+# dev-libs/oniguruma is used for documentation
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	dev-libs/oniguruma
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	lto? ( system-llvm? (
+		|| (
+			$(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}')
+			sys-devel/mold
+		)
+	) )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${SLOT}/bin/.*
+	usr/lib/${PN}/${SLOT}/libexec/.*
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${SLOT}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	if [[ ${PV} == *9999* ]]; then
+		M=$(( $(usex miri 128 0) + ${M} ))
+	fi
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+src_unpack() {
+	if [[ ${PV} = *9999* ]]; then
+		git-r3_src_unpack
+		mkdir "${S}/.cargo" || die # The vendor script has a check for .cargo/config{,.toml}
+		touch "${S}/.cargo/config.toml" || die
+		local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+		local rust_build=""
+		local rust_host=""
+		# Configure vendor to use the portage-provided toolchain. This prevents it from
+		# attempting to fetch a `beta` toolchain from the internet.
+		cat <<- _EOF_ > "${T}/vendor-config.toml"
+			[build]
+			build = "$(rust_abi "${CBUILD}")"
+			host = ["$(rust_abi "${CHOST}")"]
+			target = ["$(rust_abi "${CHOST}")"]
+			cargo = "${rust_stage0_root}/bin/cargo"
+			rustc = "${rust_stage0_root}/bin/rustc"
+			rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		_EOF_
+		# We're using git sources so we need to run the Vendor script
+		# to ensure that all dependencies are present and up-to-date
+		mkdir "${S}/vendor" || die
+		# This also compiles the 'build helper', there's no way to avoid this.
+		${EPYTHON} "${S}"/x.py vendor -v --config="${T}"/vendor-config.toml -j$(makeopts_jobs) ||
+			die "Failed to vendor dependencies"
+		# TODO: This has to be generated somehow, this is from a 1.84.x tarball I had lying around.
+		cat <<- _EOF_ > "${S}/.cargo/config.toml"
+			[source.crates-io]
+			replace-with = "vendored-sources"
+
+			[source."git+https://github.com/rust-lang/team"]
+			git = "https://github.com/rust-lang/team"
+			replace-with = "vendored-sources"
+
+			[source.vendored-sources]
+			directory = "vendor"
+		_EOF_
+	elif use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	if [[ ${PV} = *9999* ]]; then
+		# We need to update / generate lockfiles for the workspace
+		${CARGO} generate-lockfile --offline || die "Failed to generate lockfiles"
+	fi
+
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	if use lto && tc-is-clang && ! tc-ld-is-lld && ! tc-ld-is-mold; then
+		export RUSTFLAGS+=" -C link-arg=-fuse-ld=lld"
+	fi
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	# Avoid bundled copies of libraries
+	export RUSTONIG_SYSTEM_LIBONIG=1
+	# Need to check if these can be optional
+	#export LIBSQLITE3_SYS_USE_PKG_CONFIG=1
+	#export LIBSSH2_SYS_USE_PKG_CONFIG=1
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	if [[ ${PV} == *9999* ]]; then
+		use miri && tools+=',"miri"'
+	fi
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	local build_channel
+	local build_miri="false"
+	case "${PV}" in
+		*9999*)
+			build_channel="nightly"
+			;;
+		*beta*)
+			build_channel="beta"
+			;;
+		*)
+			build_channel="stable"
+			;;
+	esac
+	cat <<- _EOF_ > "${S}"/config.toml
+		# https://github.com/rust-lang/rust/issues/135358 (bug #947897)
+		profile = "dist"
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		description = "gentoo"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${SLOT}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		channel = "${build_channel}"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		$(if use lto && tc-is-clang && ! tc-ld-is-mold; then
+			echo "use-lld = true"
+		fi)
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${SLOT}/share/man/
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${SLOT}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	if [[ ${PV} = *9999* ]]; then
+		use miri && symlinks+=( miri cargo-miri )
+	fi
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV%%_*}"
+		if [[ -f "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" "${ED}/usr/lib/${PN}/${SLOT}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${SLOT}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${SLOT}/lib" "/usr/lib/${PN}/lib-${SLOT}"
+	use rust-analyzer && dosym "${SLOT}/libexec" "/usr/lib/${PN}/libexec-${SLOT}"
+	dosym "${SLOT}/share/man" "/usr/lib/${PN}/man-${SLOT}"
+	dosym "rust/${SLOT}/lib/rustlib" "/usr/lib/rustlib-${SLOT}"
+	dosym "../../lib/${PN}/${SLOT}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${SLOT}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${PN}-${SLOT}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if [[ ${SLOT} == *9999* ]] && use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${PN}-${SLOT}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/config.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${SLOT}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.88.0.ebuild b/dev-lang/rust/rust-1.88.0.ebuild
new file mode 100644
index 000000000000..5226b4e7767f
--- /dev/null
+++ b/dev-lang/rust/rust-1.88.0.ebuild
@@ -0,0 +1,837 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 20 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER=${PVR}
+
+RUST_MAX_VER=${PV%%_*}
+if [[ ${PV} == *9999* ]]; then
+	RUST_MIN_VER="1.88.0" # Update this as new `beta` releases come out.
+elif [[ ${PV} == *beta* ]]; then
+	RUST_MAX_VER="$(ver_cut 1).$(ver_cut 2).0"
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+else
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+fi
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature \
+	multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language originally developed by Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.87.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV%%_*}" # Beta releases get to share the same SLOT as the eventual stable
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto rustfmt rust-analyzer rust-src +system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+if [[ ${PV} = *9999* ]]; then
+	# These USE flags require nightly rust
+	IUSE+=" miri"
+fi
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+# dev-libs/oniguruma is used for documentation
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	dev-libs/oniguruma
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	lto? ( system-llvm? (
+		|| (
+			$(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}')
+			sys-devel/mold
+		)
+	) )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${SLOT}/bin/.*
+	usr/lib/${PN}/${SLOT}/libexec/.*
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${SLOT}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	if [[ ${PV} == *9999* ]]; then
+		M=$(( $(usex miri 128 0) + ${M} ))
+	fi
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+rust_live_get_sources() {
+	EGIT_REPO_URI="
+		https://anongit.gentoo.org/git/proj/rust-patches.git
+	"
+	EGIT_CHECKOUT_DIR="${WORKDIR}/rust-patches-${RUST_PATCH_VER}"
+	git-r3_src_unpack
+
+	EGIT_REPO_URI="
+		https://github.com/rust-lang/rust.git
+	"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+	S="${WORKDIR}/rust"
+	EGIT_CHECKOUT_DIR="${S}"
+	git-r3_src_unpack
+}
+
+src_unpack() {
+	if [[ ${PV} == *9999* ]] ; then
+		rust_live_get_sources
+
+		# Vendor dependencies
+		mkdir "${S}/.cargo" || die # The vendor script has a check for .cargo/config{,.toml}
+		touch "${S}/.cargo/bootstrap.toml" || die
+		local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+		# Configure vendor to use the portage-provided toolchain. This prevents it from
+		# attempting to fetch a `beta` toolchain from the internet.
+		cat <<- _EOF_ > "${T}/vendor-bootstrap.toml"
+			# Suppresses a warning about tracking changes which we don't care about.
+			change-id = "ignore"
+			[build]
+			build = "$(rust_abi "${CBUILD}")"
+			host = ["$(rust_abi "${CHOST}")"]
+			target = ["$(rust_abi "${CHOST}")"]
+			cargo = "${rust_stage0_root}/bin/cargo"
+			rustc = "${rust_stage0_root}/bin/rustc"
+			rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		_EOF_
+		# We're using git sources so we need to run the Vendor script
+		# to ensure that all dependencies are present and up-to-date
+		mkdir "${S}/vendor" || die
+		# This also compiles the 'build helper', there's no way to avoid this.
+		${EPYTHON} "${S}"/x.py vendor -v --config="${T}"/vendor-bootstrap.toml -j$(makeopts_jobs) ||
+			die "Failed to vendor dependencies"
+		# TODO: This has to be generated somehow, this is from a 1.84.x tarball I had lying around.
+		cat <<- _EOF_ > "${S}/.cargo/config.toml"
+			[source.crates-io]
+			replace-with = "vendored-sources"
+
+			[source."git+https://github.com/rust-lang/team"]
+			git = "https://github.com/rust-lang/team"
+			replace-with = "vendored-sources"
+
+			[source.vendored-sources]
+			directory = "vendor"
+		_EOF_
+	elif use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	if [[ ${PV} = *9999* ]]; then
+		# We need to update / generate lockfiles for the workspace
+		${CARGO} generate-lockfile --offline || die "Failed to generate lockfiles"
+	fi
+
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	if use lto && tc-is-clang && ! tc-ld-is-lld && ! tc-ld-is-mold; then
+		export RUSTFLAGS+=" -C link-arg=-fuse-ld=lld"
+	fi
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	# Avoid bundled copies of libraries
+	export RUSTONIG_SYSTEM_LIBONIG=1
+	# Need to check if these can be optional
+	#export LIBSQLITE3_SYS_USE_PKG_CONFIG=1
+	#export LIBSSH2_SYS_USE_PKG_CONFIG=1
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	if [[ ${PV} == *9999* ]]; then
+		use miri && tools+=',"miri"'
+	fi
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	local build_channel
+	local build_miri="false"
+	case "${PV}" in
+		*9999*)
+			build_channel="nightly"
+			;;
+		*beta*)
+			build_channel="beta"
+			;;
+		*)
+			build_channel="stable"
+			;;
+	esac
+	cat <<- _EOF_ > "${S}"/bootstrap.toml
+		# Suppresses a warning about tracking changes which we don't care about.
+		change-id = "ignore"
+		# https://github.com/rust-lang/rust/issues/135358 (bug #947897)
+		profile = "dist"
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		description = "gentoo"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${SLOT}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		channel = "${build_channel}"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		omit-git-hash = false
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		$(if use lto && tc-is-clang && ! tc-ld-is-mold; then
+			echo "use-lld = true"
+		fi)
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" bootstrap.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "bootstrap.toml contents:"
+	cat "${S}"/bootstrap.toml || die
+	echo
+}
+
+src_compile() {
+	# -v will show invocations, -vv "very verbose" is overkill, -vvv "very very verbose" is insane
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/bootstrap.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${SLOT}/share/man/
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${SLOT}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	if [[ ${PV} = *9999* ]]; then
+		use miri && symlinks+=( miri cargo-miri )
+	fi
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV%%_*}"
+		if [[ -f "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" "${ED}/usr/lib/${PN}/${SLOT}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${SLOT}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${SLOT}/lib" "/usr/lib/${PN}/lib-${SLOT}"
+	use rust-analyzer && dosym "${SLOT}/libexec" "/usr/lib/${PN}/libexec-${SLOT}"
+	dosym "${SLOT}/share/man" "/usr/lib/${PN}/man-${SLOT}"
+	dosym "rust/${SLOT}/lib/rustlib" "/usr/lib/rustlib-${SLOT}"
+	dosym "../../lib/${PN}/${SLOT}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${SLOT}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${PN}-${SLOT}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if [[ ${SLOT} == *9999* ]] && use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${PN}-${SLOT}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${SLOT}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.89.0.ebuild b/dev-lang/rust/rust-1.89.0.ebuild
new file mode 100644
index 000000000000..5226b4e7767f
--- /dev/null
+++ b/dev-lang/rust/rust-1.89.0.ebuild
@@ -0,0 +1,837 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 20 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER=${PVR}
+
+RUST_MAX_VER=${PV%%_*}
+if [[ ${PV} == *9999* ]]; then
+	RUST_MIN_VER="1.88.0" # Update this as new `beta` releases come out.
+elif [[ ${PV} == *beta* ]]; then
+	RUST_MAX_VER="$(ver_cut 1).$(ver_cut 2).0"
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+else
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+fi
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature \
+	multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language originally developed by Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.87.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV%%_*}" # Beta releases get to share the same SLOT as the eventual stable
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto rustfmt rust-analyzer rust-src +system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+if [[ ${PV} = *9999* ]]; then
+	# These USE flags require nightly rust
+	IUSE+=" miri"
+fi
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+# dev-libs/oniguruma is used for documentation
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	dev-libs/oniguruma
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	lto? ( system-llvm? (
+		|| (
+			$(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}')
+			sys-devel/mold
+		)
+	) )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${SLOT}/bin/.*
+	usr/lib/${PN}/${SLOT}/libexec/.*
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${SLOT}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	if [[ ${PV} == *9999* ]]; then
+		M=$(( $(usex miri 128 0) + ${M} ))
+	fi
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+rust_live_get_sources() {
+	EGIT_REPO_URI="
+		https://anongit.gentoo.org/git/proj/rust-patches.git
+	"
+	EGIT_CHECKOUT_DIR="${WORKDIR}/rust-patches-${RUST_PATCH_VER}"
+	git-r3_src_unpack
+
+	EGIT_REPO_URI="
+		https://github.com/rust-lang/rust.git
+	"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+	S="${WORKDIR}/rust"
+	EGIT_CHECKOUT_DIR="${S}"
+	git-r3_src_unpack
+}
+
+src_unpack() {
+	if [[ ${PV} == *9999* ]] ; then
+		rust_live_get_sources
+
+		# Vendor dependencies
+		mkdir "${S}/.cargo" || die # The vendor script has a check for .cargo/config{,.toml}
+		touch "${S}/.cargo/bootstrap.toml" || die
+		local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+		# Configure vendor to use the portage-provided toolchain. This prevents it from
+		# attempting to fetch a `beta` toolchain from the internet.
+		cat <<- _EOF_ > "${T}/vendor-bootstrap.toml"
+			# Suppresses a warning about tracking changes which we don't care about.
+			change-id = "ignore"
+			[build]
+			build = "$(rust_abi "${CBUILD}")"
+			host = ["$(rust_abi "${CHOST}")"]
+			target = ["$(rust_abi "${CHOST}")"]
+			cargo = "${rust_stage0_root}/bin/cargo"
+			rustc = "${rust_stage0_root}/bin/rustc"
+			rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		_EOF_
+		# We're using git sources so we need to run the Vendor script
+		# to ensure that all dependencies are present and up-to-date
+		mkdir "${S}/vendor" || die
+		# This also compiles the 'build helper', there's no way to avoid this.
+		${EPYTHON} "${S}"/x.py vendor -v --config="${T}"/vendor-bootstrap.toml -j$(makeopts_jobs) ||
+			die "Failed to vendor dependencies"
+		# TODO: This has to be generated somehow, this is from a 1.84.x tarball I had lying around.
+		cat <<- _EOF_ > "${S}/.cargo/config.toml"
+			[source.crates-io]
+			replace-with = "vendored-sources"
+
+			[source."git+https://github.com/rust-lang/team"]
+			git = "https://github.com/rust-lang/team"
+			replace-with = "vendored-sources"
+
+			[source.vendored-sources]
+			directory = "vendor"
+		_EOF_
+	elif use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	if [[ ${PV} = *9999* ]]; then
+		# We need to update / generate lockfiles for the workspace
+		${CARGO} generate-lockfile --offline || die "Failed to generate lockfiles"
+	fi
+
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	if use lto && tc-is-clang && ! tc-ld-is-lld && ! tc-ld-is-mold; then
+		export RUSTFLAGS+=" -C link-arg=-fuse-ld=lld"
+	fi
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	# Avoid bundled copies of libraries
+	export RUSTONIG_SYSTEM_LIBONIG=1
+	# Need to check if these can be optional
+	#export LIBSQLITE3_SYS_USE_PKG_CONFIG=1
+	#export LIBSSH2_SYS_USE_PKG_CONFIG=1
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	if [[ ${PV} == *9999* ]]; then
+		use miri && tools+=',"miri"'
+	fi
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	local build_channel
+	local build_miri="false"
+	case "${PV}" in
+		*9999*)
+			build_channel="nightly"
+			;;
+		*beta*)
+			build_channel="beta"
+			;;
+		*)
+			build_channel="stable"
+			;;
+	esac
+	cat <<- _EOF_ > "${S}"/bootstrap.toml
+		# Suppresses a warning about tracking changes which we don't care about.
+		change-id = "ignore"
+		# https://github.com/rust-lang/rust/issues/135358 (bug #947897)
+		profile = "dist"
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		description = "gentoo"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${SLOT}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		channel = "${build_channel}"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		omit-git-hash = false
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		$(if use lto && tc-is-clang && ! tc-ld-is-mold; then
+			echo "use-lld = true"
+		fi)
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" bootstrap.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "bootstrap.toml contents:"
+	cat "${S}"/bootstrap.toml || die
+	echo
+}
+
+src_compile() {
+	# -v will show invocations, -vv "very verbose" is overkill, -vvv "very very verbose" is insane
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/bootstrap.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${SLOT}/share/man/
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${SLOT}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	if [[ ${PV} = *9999* ]]; then
+		use miri && symlinks+=( miri cargo-miri )
+	fi
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV%%_*}"
+		if [[ -f "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" "${ED}/usr/lib/${PN}/${SLOT}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${SLOT}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${SLOT}/lib" "/usr/lib/${PN}/lib-${SLOT}"
+	use rust-analyzer && dosym "${SLOT}/libexec" "/usr/lib/${PN}/libexec-${SLOT}"
+	dosym "${SLOT}/share/man" "/usr/lib/${PN}/man-${SLOT}"
+	dosym "rust/${SLOT}/lib/rustlib" "/usr/lib/rustlib-${SLOT}"
+	dosym "../../lib/${PN}/${SLOT}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${SLOT}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${PN}-${SLOT}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if [[ ${SLOT} == *9999* ]] && use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${PN}-${SLOT}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${SLOT}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.90.0-r1.ebuild b/dev-lang/rust/rust-1.90.0-r1.ebuild
new file mode 100644
index 000000000000..e2256d6b81f8
--- /dev/null
+++ b/dev-lang/rust/rust-1.90.0-r1.ebuild
@@ -0,0 +1,1198 @@
+# Copyright 1999-2026 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 20 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+MRUSTC_VERSION="0.12.0"
+MRUSTC_RUST_VERSION="1.90.0"
+RUST_OPTIONAL=1
+
+# We bumped the rust-patches tag without bumping the revision for
+# https://bugs.gentoo.org/963657, given that ithe patch affects only a
+# specific use case (bootstrap with Rust 1.90.0).
+RUST_PATCH_VER=${PV}_p1
+
+RUST_MAX_VER=${PV%%_*}
+if [[ ${PV} == *9999* ]]; then
+	RUST_MIN_VER="1.88.0" # Update this as new `beta` releases come out.
+elif [[ ${PV} == *beta* ]]; then
+	RUST_MAX_VER="$(ver_cut 1).$(ver_cut 2).0"
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+else
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+fi
+
+inherit check-reqs estack edo flag-o-matic llvm-r1 multiprocessing optfeature \
+	multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language originally developed by Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.87.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+# Bare metal targets which can be built on the host system and have no
+# dependency on compiler runtime, libc and unwinder.
+ALL_RUST_SYSROOTS=( bpf wasm )
+ALL_RUST_SYSROOTS=( "${ALL_RUST_SYSROOTS[@]/#/rust_sysroots_}" )
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV%%_*}" # Beta releases get to share the same SLOT as the eventual stable
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto mrustc-bootstrap"
+IUSE+=" rustfmt rust-analyzer rust-src +system-llvm test ${ALL_LLVM_TARGETS[*]} ${ALL_RUST_SYSROOTS[*]}"
+
+if [[ ${PV} = *9999* ]]; then
+	# These USE flags require nightly rust
+	IUSE+=" miri"
+fi
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	rust_sysroots_wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+# dev-libs/oniguruma is used for documentation
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	dev-libs/oniguruma
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	lto? ( system-llvm? (
+		|| (
+			$(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}')
+			sys-devel/mold
+		)
+	) )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+	mrustc-bootstrap? (
+		~dev-lang/mrustc-${MRUSTC_VERSION}
+		dev-build/cmake
+		sys-devel/gcc:*
+	)
+	!mrustc-bootstrap? ( ${RUST_DEPEND} )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	rust_sysroots_bpf? ( llvm_targets_BPF )
+	rust_sysroots_wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${SLOT}/bin/.*
+	usr/lib/${PN}/${SLOT}/libexec/.*
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${SLOT}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	if [[ ${PV} == *9999* ]]; then
+		M=$(( $(usex miri 128 0) + ${M} ))
+	fi
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex rust_sysroots_bpf 256 0) + ${M} ))
+	M=$(( $(usex rust_sysroots_wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	if use mrustc-bootstrap; then
+		if ! tc-is-gcc; then
+			# USE="mrustc-bootstrap" reqires that the build environment use GCC
+			export CC=${CHOST}-gcc
+			export CXX=${CHOST}-g++
+			tc-is-gcc || die "tc-is-gcc failed in spite of CC=${CC}"
+		fi
+	else
+		rust_pkg_setup
+	fi
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+rust_live_get_sources() {
+	EGIT_REPO_URI="
+		https://anongit.gentoo.org/git/proj/rust-patches.git
+	"
+	EGIT_CHECKOUT_DIR="${WORKDIR}/rust-patches-${RUST_PATCH_VER}"
+	git-r3_src_unpack
+
+	EGIT_REPO_URI="
+		https://github.com/rust-lang/rust.git
+	"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+	S="${WORKDIR}/rust"
+	EGIT_CHECKOUT_DIR="${S}"
+	git-r3_src_unpack
+}
+
+src_unpack() {
+	if [[ ${PV} == *9999* ]] ; then
+		rust_live_get_sources
+
+		# Vendor dependencies
+		mkdir "${S}/.cargo" || die # The vendor script has a check for .cargo/config{,.toml}
+		touch "${S}/.cargo/bootstrap.toml" || die
+		local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+		# Configure vendor to use the portage-provided toolchain. This prevents it from
+		# attempting to fetch a `beta` toolchain from the internet.
+		cat <<- _EOF_ > "${T}/vendor-bootstrap.toml"
+			# Suppresses a warning about tracking changes which we don't care about.
+			change-id = "ignore"
+			[build]
+			build = "$(rust_abi "${CBUILD}")"
+			host = ["$(rust_abi "${CHOST}")"]
+			target = ["$(rust_abi "${CHOST}")"]
+			cargo = "${rust_stage0_root}/bin/cargo"
+			rustc = "${rust_stage0_root}/bin/rustc"
+			rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		_EOF_
+		# We're using git sources so we need to run the Vendor script
+		# to ensure that all dependencies are present and up-to-date
+		mkdir "${S}/vendor" || die
+		# This also compiles the 'build helper', there's no way to avoid this.
+		${EPYTHON} "${S}"/x.py vendor -v --config="${T}"/vendor-bootstrap.toml -j$(makeopts_jobs) ||
+			die "Failed to vendor dependencies"
+		# TODO: This has to be generated somehow, this is from a 1.84.x tarball I had lying around.
+		cat <<- _EOF_ > "${S}/.cargo/config.toml"
+			[source.crates-io]
+			replace-with = "vendored-sources"
+
+			[source."git+https://github.com/rust-lang/team"]
+			git = "https://github.com/rust-lang/team"
+			replace-with = "vendored-sources"
+
+			[source.vendored-sources]
+			directory = "vendor"
+		_EOF_
+	elif use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	if [[ ${PV} = *9999* ]]; then
+		# We need to update / generate lockfiles for the workspace
+		${CARGO} generate-lockfile --offline || die "Failed to generate lockfiles"
+	fi
+
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+	# Apply patches for bootstrapping with a particular Rust version (RUST_SLOT).
+	if [[ -n ${RUST_SLOT} ]]; then # Not set set if using mrustc-bootstrap
+		local bootstrap_patchdir="${WORKDIR}/rust-patches-${RUST_PATCH_VER}/${RUST_SLOT}"
+		if [[ -d "${bootstrap_patchdir}" ]]; then
+			PATCHES+=(
+				"${bootstrap_patchdir}"
+			)
+		fi
+	fi
+
+	if use lto && tc-is-clang && ! tc-ld-is-lld && ! tc-ld-is-mold; then
+		export RUSTFLAGS+=" -C link-arg=-fuse-ld=lld"
+	fi
+
+	default
+
+	if use mrustc-bootstrap; then
+		pushd "${S}" 2>/dev/null || die
+		einfo "Applying patches to enable bootstrap with mrustc ${MRUSTC_VERSION}"
+		patch -p0 < "${BROOT}"/usr/share/mrustc-${MRUSTC_VERSION}/patches/rustc-${MRUSTC_RUST_VERSION}-src.patch ||
+			die "Failed to patch sources to enable bootstrap with mrustc"
+		popd 2>/dev/null || die
+	fi
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	# Avoid bundled copies of libraries
+	export RUSTONIG_SYSTEM_LIBONIG=1
+	# Need to check if these can be optional
+	#export LIBSQLITE3_SYS_USE_PKG_CONFIG=1
+	#export LIBSSH2_SYS_USE_PKG_CONFIG=1
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use rust_sysroots_bpf; then
+		rust_targets+=",\"bpfeb-unknown-none\",\"bpfel-unknown-none\""
+	fi
+	if use rust_sysroots_wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	if [[ ${PV} == *9999* ]]; then
+		use miri && tools+=',"miri"'
+	fi
+
+	if use mrustc-bootstrap; then
+		local rust_stage0_root="${WORKDIR}/bootstrap/rust-${PV}"
+	else
+		local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+		# in case of prefix it will be already prefixed, as --print sysroot returns full path
+		[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+	fi
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	local build_channel
+	local build_miri="false"
+	case "${PV}" in
+		*9999*)
+			build_channel="nightly"
+			;;
+		*beta*)
+			build_channel="beta"
+			;;
+		*)
+			build_channel="stable"
+			;;
+	esac
+	cat <<- _EOF_ > "${S}"/bootstrap.toml
+		# Suppresses a warning about tracking changes which we don't care about.
+		change-id = "ignore"
+		# https://github.com/rust-lang/rust/issues/135358 (bug #947897)
+		profile = "dist"
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		description = "gentoo"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${SLOT}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		channel = "${build_channel}"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		omit-git-hash = false
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex rust_sysroots_wasm))
+		$(if use lto && tc-is-clang && ! tc-ld-is-mold; then
+			echo "use-lld = true"
+		fi)
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex rust_sysroots_wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use rust_sysroots_wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+		if [[ "${cross_rust_target}" == *-uefi ]]; then
+			# Profiler is not supported on bare-metal
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				profiler = false
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" bootstrap.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "bootstrap.toml contents:"
+	cat "${S}"/bootstrap.toml || die
+	echo
+}
+
+llvm_bootstrap() {
+	# Reference ${P}/src/bootstrap/native.rs for these values
+	local llvm_cmake_opts=(
+		"-G Ninja"
+		"-DLLVM_TARGET_ARCH=${CFG_COMPILER_HOST_TRIPLE%%-*}"
+		"-DLLVM_DEFAULT_TARGET_TRIPLE=${CFG_COMPILER_HOST_TRIPLE}"
+		#;Mips;PowerPC;SystemZ;JSBackend;MSP430;Sparc;NVPTX
+		"-DLLVM_TARGETS_TO_BUILD=${BOOTSTRAP_LLVM_TARGETS:=X86;ARM;AArch64}"
+		"-DLLVM_ENABLE_ASSERTIONS=OFF"
+		"-DLLVM_INCLUDE_EXAMPLES=OFF"
+		"-DLLVM_INCLUDE_TESTS=OFF"
+		"-DLLVM_INCLUDE_DOCS=OFF"
+		"-DLLVM_INCLUDE_BENCHMARKS=OFF"
+		"-DLLVM_ENABLE_ZLIB=OFF"
+		"-DLLVM_ENABLE_TERMINFO=OFF"
+		"-DLLVM_ENABLE_LIBEDIT=OFF"
+		"-DCMAKE_CXX_COMPILER=$(tc-getCXX)"
+		"-DCMAKE_C_COMPILER=$(tc-getCC)"
+		"-DCMAKE_BUILD_TYPE=Release"
+	)
+
+	if [[ -z "${LLVM_CMAKE_OPTS_EXTRA}" ]]; then
+		llvm_cmake_opts+=( "${LLVM_CMAKE_OPTS_EXTRA}")
+	fi
+
+	elog "Building bootstrap llvm ..."
+
+	mkdir -p "${WORKDIR}/bootstrap/llvm" || die
+	pushd "${WORKDIR}/bootstrap/llvm" 2>/dev/null || die
+		edo cmake ${llvm_cmake_opts[*]} "${S}/src/llvm-project/llvm"
+		eninja || die "Failed to build bootstrap llvm"
+	popd 2>/dev/null || die
+}
+
+# High level steps:
+# Our system mrustc package has built stdlib for our current platform.
+# - Step 1: Use system-installed mrustc, (m)rust(c) stdlib, and minicargo to
+#	bootstrap a `cargo` and `rustc` (mrustc-stage0)
+# - Step 2: Use minicargo and the built `rustc` to build a working `sysroot`
+#			(includes `std`, `panic_unwind``, `test`, etc.) (mrustc-stage0)
+# - Step 3: Build build libs again (this time using `cargo` and `rustc`) (mrustc-stage1)
+# - Step 4: Build a `rustc` using those libs (mrustc-stage1)
+#  - Done so there's an optimised rustc around (mrustc is bad at codegen)
+# - Step 5: Build `libstd` with this `rustc` (mrustc-stage2)
+#  - Needed to match ABIs
+# Stages:
+# - mrustc-stage0: mrustc-built cargo and rustc
+# - mrustc-stage1: rustc and sysroot built with mrustc-stage0
+# - mrustc-stage2: rustc from stage1 with sysroot built with stage0
+# See:
+# - https://github.com/thepowersgang/mrustc/blob/master/run_rustc/Makefile
+# - https://github.com/thepowersgang/mrustc/blob/master/TestRustcBootstrap.sh
+# - Upstream Windows .cmd files are also a good reference for early bootstrap
+mrustc_bootstrap() {
+	export RUSTC_BOOTSTRAP=1 # Possibly the only intended use of this variable in ::gentoo
+	# export these variables now and unset them at the end of the function so they don't leak
+	# into the rest of the build.
+	export CFG_COMPILER_HOST_TRIPLE="$(rust_abi)"
+	export CFG_RELEASE="${MRUSTC_RUST_VERSION}"	# Let's pretend we're 1.90.0
+	export CFG_RELEASE_CHANNEL="stable"
+	export CFG_VERSION="${MRUSTC_RUST_VERSION}-stable-mrustc"
+	export CFG_PREFIX="mrustc"
+	export CFG_LIBDIR_RELATIVE="lib"
+	# We actually patch our executable, but this suppresses a warning on every invocation of the bootstrap compiler.
+	export MRUSTC_TARGET_VER="${MRUSTC_RUST_VERSION%.*}"
+	export RUSTC_INSTALL_BINDIR="bin"
+	export REAL_LIBRARY_PATH_VAR="LD_LIBRARY_PATH"
+	export STD_ENV_ARCH="${CFG_COMPILER_HOST_TRIPLE%%-*}"
+
+	# These flags are used in every invocation of our bootstrap `cargo`.
+	local cargo_flags="--target ${CFG_COMPILER_HOST_TRIPLE} -j $(makeopts_jobs) --release --verbose"
+
+	# for bootstrap, let's using the built-in stdlib of compiler (could be the bundled one)
+	filter-flags '-stdlib=*'
+
+	# mrustc requires gcc, so disable libcxx to avoid linker failure on w/o '-lstdc++'
+	[[ "${LLVM_USE_LIBCXX}" == "1" ]] && unset LLVM_USE_LIBCXX
+
+	local llvm_config_wrapper_cxxflags=0
+
+	if use system-llvm; then
+		export LLVM_CONFIG="$(get_llvm_prefix)/bin/llvm-config"
+
+		local llvm_config_cxxflags=$(${LLVM_CONFIG} --cxxflags)
+		elog "Checking llvm-config --cxxflags: '${llvm_config_cxxflags}'"
+		[[ "${llvm_config_cxxflags}" =~ (^|[[:space:]])-stdlib=libc\+\+([[:space:]]|$) ]] && {
+			elog "Found LLVM CXXFLAGS has \"--stdlib=libc++\""
+			llvm_config_wrapper_cxxflags=1
+		}
+	else
+		llvm_bootstrap
+		export LLVM_CONFIG="${WORKDIR}/bootstrap/llvm/bin/llvm-config"
+	fi
+
+	elog "LLVM_CONFIG before wrappers: ${LLVM_CONFIG}"
+
+	# workaround for gcc bug 122409 on musl by wrapping llvm-config
+	# to append libc++ header if has "-stdlib=libc++"
+	elog "Preparing wrapper of llvm-config (${WORKDIR}/llvm-config)"
+	cat > ${WORKDIR}/llvm-config <<-EOF || die
+	#!/bin/bash
+
+	RULES=()
+	for flag in "\$@"; do
+	    case "\${flag}" in
+	$([[ "${llvm_config_wrapper_cxxflags}" == 1 ]] && {
+		echo "        --cxxflags) RULES+=( \"-E\" \"s@(^|[[:space:]]+)(-stdlib=libc\\+\\+)(\\$|[[:space:]])@\\1-I${EPREFIX}/usr/include/c++/v1 \\2\\3@g\" ) ;;"
+	})
+	        *)
+	            ;;
+	    esac
+	done
+
+	[[ -z "\${RULES}" ]] && {
+	    ${LLVM_CONFIG} "\$@"
+	} || {
+	    ${LLVM_CONFIG} "\$@" | \\
+	        tee -a ${T}/llvm-config.0.log | \\
+	        sed "\${RULES[@]}" | \\
+	        tee -a ${T}/llvm-config.1.log
+	    exit \${PIPESTATUS[0]}
+	}
+	EOF
+	export LLVM_CONFIG="${WORKDIR}/llvm-config"
+	chmod +x ${WORKDIR}/llvm-config || die
+
+	einfo "llvm-config wrapper contents:"
+	cat "${LLVM_CONFIG}" || die
+	echo
+
+	# define the mrustc sysroot and common minicargo arguments.
+	local mrustc_sysroot="${BROOT}/usr/lib/rust/mrustc-${MRUSTC_VERSION}/lib/rustlib/${CFG_COMPILER_HOST_TRIPLE}/lib"
+	local minicargo_common_args=(
+		"-L" "${mrustc_sysroot}"
+		"-j" "$(makeopts_jobs)"
+		"--vendor-dir" "${S}/vendor"
+		"--manifest-overrides"
+		"${BROOT}/usr/share/mrustc-${MRUSTC_VERSION}/patches/rustc-${MRUSTC_RUST_VERSION}-overrides.toml"
+	)
+	# There's a very good chance that minicargo and mrustc are not in the PATH.
+	if ! command -v minicargo &> /dev/null; then
+		export PATH="${BROOT}/usr/lib/rust/mrustc-${MRUSTC_VERSION}/bin:${PATH}"
+	fi
+	# Sanity check our bootstrap compiler & stdlib.
+	elog "Sanity checking mrustc and stdlib ..."
+	edo mrustc "${S}/tests/ui/parallel-rustc/hello_world.rs" -L "${mrustc_sysroot}" -o "${T}"/hello -g
+	"${T}"/hello || die "Failed to run hello_world"
+	# Seems fine, let's build some tools!
+
+	# Step 1: Build a `cargo` and `rustc` using system-installed mrustc
+	# Anything we produce is going to be terribly unoptimised; mrustc does not do fantastic codegen.
+	# It's good enough to bootstrap the "real" rustc though.
+	elog "Building bootstrap cargo and rustc using mrustc and minicargo (mrustc-stage0) ..."
+	local stage0="${WORKDIR}/bootstrap/mrustc-stage0"
+	mkdir -p "${stage0}" || die
+	edo minicargo "${S}"/src/tools/cargo --output-dir "${stage0}"/cargo-build ${minicargo_common_args[*]}
+	"${stage0}"/cargo-build/cargo --version || die "Bootstrap cargo failed basic sanity check"
+	edo minicargo "${S}"/compiler/rustc --output-dir "${stage0}"/rustc-build ${minicargo_common_args[*]} \
+		--features llvm
+	"${stage0}"/rustc-build/rustc_main --version || die "Bootstrap rustc failed basic sanity check"
+	# minicargo has special-casing for `rustc` so we need to rename it.
+	mv "${stage0}"/rustc-build/rustc_main "${stage0}"/rustc-build/rustc || die "Failed to rename rustc_main to rustc"
+	# rustc wants these here
+	mkdir -p "${stage0}"/codegen-backends || die
+	mv "${stage0}"/rustc-build/librustc_codegen_llvm.* "${stage0}"/codegen-backends || die
+
+	# Step 2: use the bootstrapped rustc to build sysroot; we need to use `minicargo` for this -
+	# mrustc does not accept all of the arguments that rustc does, even with the rustc_proxy wrapper.
+	# `--script-overrides`:  If the overrides are available, build scripts (and build-deps) are not built
+	# which is good since we don't have a working compiler yet, and can't build them.
+
+	local stage0_sysroot_lib="${stage0}/lib/rustlib/${CFG_COMPILER_HOST_TRIPLE}/lib"
+	# minicargo <= 0.12.0 doesn't create this directory and silently fails, besides it's better to be explicit, right?
+	mkdir -p "${stage0_sysroot_lib}" || die "Failed to create stage0 directory"
+
+	elog "Building 'sysroot' using bootstrap rustc (mrustc-stage0) ..."
+	local o_dir="${BROOT}/usr/share/mrustc-${MRUSTC_VERSION}/script-overrides/stable-${MRUSTC_RUST_VERSION}-linux/"
+	edo env MRUSTC_PATH="${stage0}/rustc-build/rustc" minicargo -j $(makeopts_jobs) --vendor-dir "${S}"/vendor \
+		--script-overrides  "${o_dir}" \
+		--output-dir "${stage0_sysroot_lib}" "${S}"/library/sysroot ||
+			die "Failed to build sysroot with bootstrap rust (mrustc-stage0)"
+
+	elog "Sanity checking sysroot and rustc ..."
+	mkdir -p "${T}"/stage0-hello || die
+	edo "${stage0}"/rustc-build/rustc -L "${stage0_sysroot_lib}" -g "${S}/tests/ui/parallel-rustc/hello_world.rs" \
+		-o "${T}"/stage0-hello/hello
+	"${T}"/stage0-hello/hello || die "Failed to run hello_world built with bootstrap rust stage0"
+
+	elog "mrustc bootstrap stage0 complete!"
+
+	# Step 3: Build a "proper" libstd, including dynamic libs using our bootstrap cargo and rustc.
+	elog "Building 'sysroot' with the stage0 rustc (mrustc-stage1) ..."
+	local stage1="${WORKDIR}/bootstrap/mrustc-stage1"
+	local stage1_sysroot_lib="${stage1}/lib/rustlib/${CFG_COMPILER_HOST_TRIPLE}/lib"
+	mkdir -p "${stage1_sysroot_lib}" || die "Failed to create stage1 directory"
+	mkdir -p "${stage1}/bin" || die
+
+	# Simplified to avoid calling rustc_proxy; We don't need stage1 rustc until after this is built...
+	edo env RUSTFLAGS="-Z force-unstable-if-unmarked" CARGO_TARGET_DIR="${stage1}/sysroot-build" \
+		RUSTC="${stage0}/rustc-build/rustc" "${stage0}"/cargo-build/cargo build ${cargo_flags} \
+		--manifest-path "${S}/library/sysroot/Cargo.toml" --features panic-unwind
+
+	# Move the built libs into the sysroot libdir.
+	mv "${stage1}/sysroot-build/${CFG_COMPILER_HOST_TRIPLE}/release/deps"/*.{rlib,rmeta,so} \
+		"${stage1_sysroot_lib}" || die "Failed to move stage1 libs to stage1 sysroot"
+
+	# We need to copy the stage0 rustc to the stage1 sysroot; this "updates" the sysroot location and enables
+	# resolution of stage1 libs. (run `rustc --print sysroot` on stage0 and stage1 rustc to verify)
+	cp "${stage0}/rustc-build/rustc" "${stage1}/bin/rustc" || die "Failed to copy rustc to stage1 sysroot"
+
+	# Step 4: Build `rustc` with itself, so we have a rustc with the right ABI.
+	# This will be our final `rustc` for the bootstrap process.
+	elog "Building rustc with stage1 libs (mrustc-stage1) ..."
+	mkdir -p "${stage1}/rustc-build" || die
+	edo env RUSTFLAGS="-Z force-unstable-if-unmarked -C link_args=-Wl,-rpath,\$ORIGIN/../lib" \
+		LD_LIBRARY_PATH="${stage2_sysroot_lib}" CARGO_TARGET_DIR="${stage1}/rustc-build" \
+		RUSTC="${stage1}/bin/rustc" TMPDIR="${T}" "${stage0}"/cargo-build/cargo build ${cargo_flags} \
+		--manifest-path "${S}/compiler/rustc/Cargo.toml"  --features llvm
+
+	# Step 5: Build `sysroot` with this `rustc` - Needed to match ABI
+	# We need to use the previous sysroot; we could reuse that dir but it's easier to just copy it.
+	elog "Building final 'sysroot' with the final rustc (mrustc-stage2) ..."
+	local stage2="${WORKDIR}/bootstrap/mrustc-stage2"
+	local stage2_sysroot_lib="${stage2}/lib/rustlib/${CFG_COMPILER_HOST_TRIPLE}/lib"
+	mkdir -p "${stage2_sysroot_lib}" || die "Failed to create stage2 directory"
+	mkdir -p "${stage2}/bin" || die
+
+	# Copy required files from stage1 to stage2 sysroot
+	cp "${stage1}/rustc-build/${CFG_COMPILER_HOST_TRIPLE}"/release/rustc-main "${stage2}/bin/rustc_binary" ||
+		die "Failed to copy final rustc to stage2 sysroot"
+	cp "${stage1}/rustc-build/${CFG_COMPILER_HOST_TRIPLE}"/release/librustc_driver.so "${stage2}/lib" ||
+		die "Failed to copy librustc_driver to sysroot"
+	cp "${stage1}/rustc-build/${CFG_COMPILER_HOST_TRIPLE}"/release/deps/*.{rlib,so} "${stage2_sysroot_lib}" ||
+		die "Failed to copy final rustc libs to stage2 sysroot"
+	cp "${stage1_sysroot_lib}"/* "${stage2_sysroot_lib}" || die "Failed to copy stage1 so files to stage2 sysroot"
+
+	# There's a magic script used in place of rustc so that libs can be found
+	cat <<- EOF > "${stage2}/bin/rustc" || die "Failed to create rustc wrapper"
+		#!/bin/sh
+		LD_LIBRARY_PATH="${stage2}/lib:${stage2_sysroot_lib}" ${stage2}/bin/rustc_binary "\$@"
+	EOF
+	chmod +x "${stage2}/bin/rustc" || die "Failed to make rustc wrapper executable"
+
+	# Use rustc to build 'sysroot'; this is the final step in the bootstrap process.
+	# rpath probably isn't needed here, but it doesn't hurt.
+	edo env RUSTFLAGS="-Z force-unstable-if-unmarked -C link_args=-Wl,-rpath,\$ORIGIN/../lib" \
+		CARGO_TARGET_DIR="${stage2}/stdlib-build" RUSTC="${stage2}/bin/rustc" \
+		"${stage0}"/cargo-build/cargo build ${cargo_flags} --manifest-path "${S}/library/sysroot/Cargo.toml" \
+		--features panic-unwind
+
+	# Build our final output sysroot
+	local output="${WORKDIR}/bootstrap/rust-${PV}"
+	local output_sysroot_lib="${output}/lib/rustlib/${CFG_COMPILER_HOST_TRIPLE}/lib"
+	mkdir -p "${output_sysroot_lib}" || die "Failed to create output directory"
+	mkdir -p "${output}/bin" || die "Failed to create output directory"
+
+	# Copy our various output files into the output sysroot
+	# rustc
+	cp "${stage1}/rustc-build/${CFG_COMPILER_HOST_TRIPLE}"/release/rustc-main "${output}/bin/rustc_binary" ||
+		die "Failed to copy final rustc to output"
+	cp "${stage1}/rustc-build/${CFG_COMPILER_HOST_TRIPLE}"/release/librustc_driver.so "${output}/lib" ||
+		die "Failed to copy librustc_driver to output"
+	cp "${stage1}/rustc-build/${CFG_COMPILER_HOST_TRIPLE}"/release/deps/*.{rlib,so} "${output_sysroot_lib}" ||
+		die "Failed to copy final rustc libs to output"
+	# cargo; no need to build an optimised cargo if we're using this to build a complelety new Rust.
+	cp "${stage0}/cargo-build/cargo" "${output}/bin/cargo" || die "Failed to copy cargo to output"
+	# libs
+	mv "${stage2}/stdlib-build/${CFG_COMPILER_HOST_TRIPLE}/release/deps"/*.{rlib,rmeta,so} "${output_sysroot_lib}" ||
+		die "Failed to copy stage2 libs to output"
+	# Our trusty rustc wrapper
+	cat <<- EOF > "${output}/bin/rustc" || die "Failed to create rustc wrapper"
+		#!/bin/sh
+		LD_LIBRARY_PATH="${output}/lib:${output_sysroot_lib}" ${output}/bin/rustc_binary "\$@"
+	EOF
+	chmod +x "${output}/bin/rustc" || die "Failed to make rustc wrapper executable"
+
+	# Perform a sanity check on the final Rust.
+	mkdir -p "${T}"/output-hello || die
+	edo "${output}/bin/rustc" -L "${output_sysroot_lib}" -g "${S}/tests/ui/parallel-rustc/hello_world.rs" \
+		-o "${T}"/output-hello/hello
+	"${T}"/output-hello/hello || die "Failed to run hello_world built with bootstrapped Rust"
+
+	elog "Successfully bootstrapped Rust using mrustc!"
+
+	# Note: The Rust sysroot that we've produced is pretty close to what we'd expect from a normal Rust build.
+	# If someone was so inclined they could build an optimised cargo using the stage2 rustc and sysroot,
+	# and install the output directly. This is untested, as I'm sure there's more to it than that.
+	# I'm satisfied with being able to build Rust normally at this point.
+
+	# Tidy up the Rust sources; revert mrustc changes so Rust can be built normally.
+	pushd "${S}" 2>/dev/null || die
+		patch -R -p0 < "${BROOT}"/usr/share/mrustc-${MRUSTC_VERSION}/patches/rustc-${MRUSTC_RUST_VERSION}-src.patch ||
+			die "Failed to revert mrustc patches"
+	popd 2>/dev/null || die
+
+	# Tidy up any environment variables we've set in the bootstrap process.
+	unset CFG_COMPILER_HOST_TRIPLE CFG_RELEASE CFG_RELEASE_CHANNEL CFG_PREFIX CFG_VERSION CFG_LIBDIR_RELATIVE
+	unset LLVM_CONFIG MRUSTC_TARGET_VER REAL_LIBRARY_PATH_VAR RUSTFLAGS RUSTC_BOOTSTRAP RUSTC_INSTALL_BINDIR
+}
+
+src_compile() {
+	use mrustc-bootstrap && mrustc_bootstrap
+	# -v will show invocations, -vv "very verbose" is overkill, -vvv "very very verbose" is insane
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/bootstrap.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${SLOT}/share/man/
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${SLOT}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	if [[ ${PV} = *9999* ]]; then
+		use miri && symlinks+=( miri cargo-miri )
+	fi
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV%%_*}"
+		if [[ -f "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" "${ED}/usr/lib/${PN}/${SLOT}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${SLOT}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${SLOT}/lib" "/usr/lib/${PN}/lib-${SLOT}"
+	use rust-analyzer && dosym "${SLOT}/libexec" "/usr/lib/${PN}/libexec-${SLOT}"
+	dosym "${SLOT}/share/man" "/usr/lib/${PN}/man-${SLOT}"
+	dosym "rust/${SLOT}/lib/rustlib" "/usr/lib/rustlib-${SLOT}"
+	dosym "../../lib/${PN}/${SLOT}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${SLOT}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${PN}-${SLOT}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if [[ ${SLOT} == *9999* ]] && use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${PN}-${SLOT}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${SLOT}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.91.0.ebuild b/dev-lang/rust/rust-1.91.0.ebuild
new file mode 100644
index 000000000000..8c98a388efaf
--- /dev/null
+++ b/dev-lang/rust/rust-1.91.0.ebuild
@@ -0,0 +1,859 @@
+# Copyright 1999-2026 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+# Bump notes: https://wiki.gentoo.org/wiki/Project:Rust/Rust_bump
+
+LLVM_COMPAT=( 21 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+RUST_PATCH_VER=${PV#*_p}
+RUST_MAX_VER=${PV%%_*}
+
+if [[ ${PV} == *9999* ]]; then
+	RUST_MIN_VER="1.88.0" # Update this as new `beta` releases come out.
+elif [[ ${PV} == *beta* ]]; then
+	RUST_MAX_VER="$(ver_cut 1).$(ver_cut 2).0"
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+else
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+fi
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature \
+	multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+			-> rustc-${PV}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${PV}"
+	SRC_URI="https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language originally developed by Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.87.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+# Bare metal targets which can be built on the host system and have no
+# dependency on compiler runtime, libc and unwinder.
+ALL_RUST_SYSROOTS=( bpf wasm )
+ALL_RUST_SYSROOTS=( "${ALL_RUST_SYSROOTS[@]/#/rust_sysroots_}" )
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV%%_*}" # Beta releases get to share the same SLOT as the eventual stable
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto rustfmt rust-analyzer rust-src +system-llvm test ${ALL_LLVM_TARGETS[*]} ${ALL_RUST_SYSROOTS[*]}"
+
+if [[ ${PV} = *9999* ]]; then
+	# These USE flags require nightly rust
+	IUSE+=" miri"
+fi
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	rust_sysroots_wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+# dev-libs/oniguruma is used for documentation
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	dev-libs/oniguruma
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	lto? ( system-llvm? (
+		|| (
+			$(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}')
+			sys-devel/mold
+		)
+	) )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	rust_sysroots_bpf? ( llvm_targets_BPF )
+	rust_sysroots_wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${SLOT}/bin/.*
+	usr/lib/${PN}/${SLOT}/libexec/.*
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${SLOT}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	if [[ ${PV} == *9999* ]]; then
+		M=$(( $(usex miri 128 0) + ${M} ))
+	fi
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex rust_sysroots_bpf 256 0) + ${M} ))
+	M=$(( $(usex rust_sysroots_wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+rust_live_get_sources() {
+	EGIT_REPO_URI="
+		https://anongit.gentoo.org/git/proj/rust-patches.git
+	"
+	EGIT_CHECKOUT_DIR="${WORKDIR}/rust-patches-${RUST_PATCH_VER}"
+	git-r3_src_unpack
+
+	EGIT_REPO_URI="
+		https://github.com/rust-lang/rust.git
+	"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+	S="${WORKDIR}/rust"
+	EGIT_CHECKOUT_DIR="${S}"
+	git-r3_src_unpack
+}
+
+src_unpack() {
+	if [[ ${PV} == *9999* ]] ; then
+		rust_live_get_sources
+
+		# Vendor dependencies
+		mkdir "${S}/.cargo" || die # The vendor script has a check for .cargo/config{,.toml}
+		touch "${S}/.cargo/bootstrap.toml" || die
+		local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+		# Configure vendor to use the portage-provided toolchain. This prevents it from
+		# attempting to fetch a `beta` toolchain from the internet.
+		cat <<- _EOF_ > "${T}/vendor-bootstrap.toml"
+			# Suppresses a warning about tracking changes which we don't care about.
+			change-id = "ignore"
+			[build]
+			build = "$(rust_abi "${CBUILD}")"
+			host = ["$(rust_abi "${CHOST}")"]
+			target = ["$(rust_abi "${CHOST}")"]
+			cargo = "${rust_stage0_root}/bin/cargo"
+			rustc = "${rust_stage0_root}/bin/rustc"
+			rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		_EOF_
+		# We're using git sources so we need to run the Vendor script
+		# to ensure that all dependencies are present and up-to-date
+		mkdir "${S}/vendor" || die
+		# This also compiles the 'build helper', there's no way to avoid this.
+		${EPYTHON} "${S}"/x.py vendor -v --config="${T}"/vendor-bootstrap.toml -j$(makeopts_jobs) ||
+			die "Failed to vendor dependencies"
+		# TODO: This has to be generated somehow, this is from a 1.84.x tarball I had lying around.
+		cat <<- _EOF_ > "${S}/.cargo/config.toml"
+			[source.crates-io]
+			replace-with = "vendored-sources"
+
+			[source."git+https://github.com/rust-lang/team"]
+			git = "https://github.com/rust-lang/team"
+			replace-with = "vendored-sources"
+
+			[source.vendored-sources]
+			directory = "vendor"
+		_EOF_
+	elif use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	if [[ ${PV} = *9999* ]]; then
+		# We need to update / generate lockfiles for the workspace
+		${CARGO} generate-lockfile --offline || die "Failed to generate lockfiles"
+	fi
+
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	if use lto && tc-is-clang && ! tc-ld-is-lld && ! tc-ld-is-mold; then
+		export RUSTFLAGS+=" -C link-arg=-fuse-ld=lld"
+	fi
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	# Avoid bundled copies of libraries
+	export RUSTONIG_SYSTEM_LIBONIG=1
+	# Need to check if these can be optional
+	#export LIBSQLITE3_SYS_USE_PKG_CONFIG=1
+	#export LIBSSH2_SYS_USE_PKG_CONFIG=1
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use rust_sysroots_bpf; then
+		rust_targets+=",\"bpfeb-unknown-none\",\"bpfel-unknown-none\""
+	fi
+	if use rust_sysroots_wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	if [[ ${PV} == *9999* ]]; then
+		use miri && tools+=',"miri"'
+	fi
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	local build_channel
+	local build_miri="false"
+	case "${PV}" in
+		*9999*)
+			build_channel="nightly"
+			;;
+		*beta*)
+			build_channel="beta"
+			;;
+		*)
+			build_channel="stable"
+			;;
+	esac
+
+	# TODO: Add optimized-compiler-builtins for system-llvm to avoid
+	# building bundled compiler-rt.
+	cat <<- _EOF_ > "${S}"/bootstrap.toml
+		# Suppresses a warning about tracking changes which we don't care about.
+		change-id = "ignore"
+		# https://github.com/rust-lang/rust/issues/135358 (bug #947897)
+		profile = "dist"
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		description = "gentoo"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${SLOT}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		channel = "${build_channel}"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		omit-git-hash = false
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex rust_sysroots_wasm))
+		$(if use lto && tc-is-clang && ! tc-ld-is-mold; then
+			echo "use-lld = true"
+		fi)
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex rust_sysroots_wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use rust_sysroots_wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+		if [[ "${cross_rust_target}" == *-uefi ]]; then
+			# Profiler is not supported on bare-metal
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				profiler = false
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" bootstrap.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "bootstrap.toml contents:"
+	cat "${S}"/bootstrap.toml || die
+	echo
+}
+
+src_compile() {
+	# -v will show invocations, -vv "very verbose" is overkill, -vvv "very very verbose" is insane
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/bootstrap.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${SLOT}/share/man/
+
+	# bash-completion files are installed by dev-lang/rust-common instead
+	# bug #689562, #689160.
+	rm -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d" || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	if [[ ${PV} = *9999* ]]; then
+		use miri && symlinks+=( miri cargo-miri )
+	fi
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV%%_*}"
+		if [[ -f "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" "${ED}/usr/lib/${PN}/${SLOT}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${SLOT}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${SLOT}/lib" "/usr/lib/${PN}/lib-${SLOT}"
+	use rust-analyzer && dosym "${SLOT}/libexec" "/usr/lib/${PN}/libexec-${SLOT}"
+	dosym "${SLOT}/share/man" "/usr/lib/${PN}/man-${SLOT}"
+	dosym "rust/${SLOT}/lib/rustlib" "/usr/lib/rustlib-${SLOT}"
+	dosym "../../lib/${PN}/${SLOT}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${SLOT}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${PN}-${SLOT}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if [[ ${SLOT} == *9999* ]] && use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${PN}-${SLOT}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${SLOT}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.92.0_p1-r1.ebuild b/dev-lang/rust/rust-1.92.0_p1-r1.ebuild
new file mode 100644
index 000000000000..cf8f4817457c
--- /dev/null
+++ b/dev-lang/rust/rust-1.92.0_p1-r1.ebuild
@@ -0,0 +1,891 @@
+# Copyright 1999-2026 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+# Bump notes: https://wiki.gentoo.org/wiki/Project:Rust/Rust_bump
+
+LLVM_COMPAT=( 21 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+# Patches are kept in rust-patches.git, see its README.rst for the versioning
+# scheme.
+#
+# We use _pN from the ebuild version for the patchset but it can be overridden
+# in the ebuild for changes that don't require a revbump.
+#
+# Uncomment this line when the ebuild needs a patchset update but no revbump.
+#RUST_PATCH_VER=${PV}-1
+
+RUST_MAX_VER=${PV%%_*}
+RUST_PV=${PV%%_p*}
+RUST_P=${PN}-${RUST_PV}
+[[ -z ${RUST_PATCH_VER} ]] && RUST_PATCH_VER=${PV}
+
+if [[ ${PV} == *9999* ]]; then
+	# Update this as new `beta` releases come out.
+	RUST_MIN_VER="1.88.0"
+elif [[ ${PV} == *beta* ]]; then
+	RUST_MAX_VER="$(ver_cut 1).$(ver_cut 2).0"
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+else
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+fi
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature
+inherit multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs
+inherit verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="
+		https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${RUST_PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? (
+			https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+				-> rustc-${RUST_PV}-src.tar.xz.asc
+		)
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${RUST_PV}"
+	SRC_URI="
+		https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language originally developed by Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai )
+ALL_LLVM_TARGETS+=( LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV )
+ALL_LLVM_TARGETS+=( SystemZ VE WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.87.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+# Bare metal targets which can be built on the host system and have no
+# dependency on compiler runtime, libc and unwinder.
+ALL_RUST_SYSROOTS=( bpf wasm )
+ALL_RUST_SYSROOTS=( "${ALL_RUST_SYSROOTS[@]/#/rust_sysroots_}" )
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV%%_*}" # Beta releases get to share the same SLOT as the eventual stable
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto"
+IUSE+=" rustfmt rust-analyzer rust-src +system-llvm test"
+IUSE+=" ${ALL_LLVM_TARGETS[*]} ${ALL_RUST_SYSROOTS[*]}"
+
+if [[ ${PV} = *9999* ]]; then
+	# These USE flags require nightly rust
+	IUSE+=" miri"
+fi
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	rust_sysroots_wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+# dev-libs/oniguruma is used for documentation
+BDEPEND="
+	${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	dev-libs/oniguruma
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	lto? ( system-llvm? (
+		|| (
+			$(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}')
+			sys-devel/mold
+		)
+	) )
+	rust_sysroots_wasm? ( llvm-core/clang )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="
+	${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="
+	|| ( ${ALL_LLVM_TARGETS[*]} )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	rust_sysroots_bpf? ( llvm_targets_BPF )
+	rust_sysroots_wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${SLOT}/bin/.*
+	usr/lib/${PN}/${SLOT}/libexec/.*
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${SLOT}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	if [[ ${PV} == *9999* ]]; then
+		M=$(( $(usex miri 128 0) + ${M} ))
+	fi
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex rust_sysroots_bpf 256 0) + ${M} ))
+	M=$(( $(usex rust_sysroots_wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+rust_live_get_sources() {
+	EGIT_REPO_URI="
+		https://anongit.gentoo.org/git/proj/rust-patches.git
+	"
+	EGIT_CHECKOUT_DIR="${WORKDIR}/rust-patches-${RUST_PATCH_VER}"
+	git-r3_src_unpack
+
+	EGIT_REPO_URI="
+		https://github.com/rust-lang/rust.git
+	"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+	S="${WORKDIR}/rust"
+	EGIT_CHECKOUT_DIR="${S}"
+	git-r3_src_unpack
+}
+
+src_unpack() {
+	if [[ ${PV} == *9999* ]] ; then
+		rust_live_get_sources
+
+		# Vendor dependencies
+		mkdir "${S}/.cargo" || die # The vendor script has a check for .cargo/config{,.toml}
+		touch "${S}/.cargo/bootstrap.toml" || die
+		local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+		# Configure vendor to use the portage-provided toolchain. This prevents it from
+		# attempting to fetch a `beta` toolchain from the internet.
+		cat <<- _EOF_ > "${T}/vendor-bootstrap.toml"
+			# Suppresses a warning about tracking changes which we don't care about.
+			change-id = "ignore"
+			[build]
+			build = "$(rust_abi "${CBUILD}")"
+			host = ["$(rust_abi "${CHOST}")"]
+			target = ["$(rust_abi "${CHOST}")"]
+			cargo = "${rust_stage0_root}/bin/cargo"
+			rustc = "${rust_stage0_root}/bin/rustc"
+			rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		_EOF_
+		# We're using git sources so we need to run the Vendor script
+		# to ensure that all dependencies are present and up-to-date
+		mkdir "${S}/vendor" || die
+		# This also compiles the 'build helper', there's no way to avoid this.
+		${EPYTHON} "${S}"/x.py vendor -v --config="${T}"/vendor-bootstrap.toml -j$(makeopts_jobs) ||
+			die "Failed to vendor dependencies"
+		# TODO: This has to be generated somehow, this is from a 1.84.x tarball I had lying around.
+		cat <<- _EOF_ > "${S}/.cargo/config.toml"
+			[source.crates-io]
+			replace-with = "vendored-sources"
+
+			[source."git+https://github.com/rust-lang/team"]
+			git = "https://github.com/rust-lang/team"
+			replace-with = "vendored-sources"
+
+			[source.vendored-sources]
+			directory = "vendor"
+		_EOF_
+	elif use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${RUST_PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	if use lto && tc-is-clang && ! tc-ld-is-lld && ! tc-ld-is-mold; then
+		export RUSTFLAGS+=" -C link-arg=-fuse-ld=lld"
+	fi
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	# Avoid bundled copies of libraries
+	export RUSTONIG_SYSTEM_LIBONIG=1
+	# Need to check if these can be optional
+	#export LIBSQLITE3_SYS_USE_PKG_CONFIG=1
+	#export LIBSSH2_SYS_USE_PKG_CONFIG=1
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use rust_sysroots_bpf; then
+		rust_targets+=",\"bpfeb-unknown-none\",\"bpfel-unknown-none\""
+	fi
+	if use rust_sysroots_wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	if [[ ${PV} == *9999* ]]; then
+		use miri && tools+=',"miri"'
+	fi
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	local build_channel
+	local build_miri="false"
+	case "${PV}" in
+		*9999*)
+			build_channel="nightly"
+			;;
+		*beta*)
+			build_channel="beta"
+			;;
+		*)
+			build_channel="stable"
+			;;
+	esac
+
+	# TODO: Add optimized-compiler-builtins for system-llvm to avoid
+	# building bundled compiler-rt.
+	cat <<- _EOF_ > "${S}"/bootstrap.toml
+		# Suppresses a warning about tracking changes which we don't care about.
+		change-id = "ignore"
+		# https://github.com/rust-lang/rust/issues/135358 (bug #947897)
+		profile = "dist"
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		description = "gentoo"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${SLOT}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		channel = "${build_channel}"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		omit-git-hash = false
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex rust_sysroots_wasm))
+		$(if use lto && tc-is-clang && ! tc-ld-is-mold; then
+			echo "use-lld = true"
+		fi)
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex rust_sysroots_wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use rust_sysroots_wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		if tc-is-clang; then
+			local wasm_cc=$(tc-getCC)
+			local wasm_cxx=$(tc-getCXX)
+		else
+			local wasm_cc=${CHOST}-clang
+			local wasm_cxx=${CHOST}-clang++
+		fi
+		export CFLAGS_${wasm_target//-/_}="$(
+			CC="${wasm_cc} --target=wasm32-unknown-unknown"
+			filter-flags '-mcpu*' '-march*' '-mtune*'
+			strip-unsupported-flags
+			echo "${CFLAGS}"
+		)"
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.wasm32-unknown-unknown]
+			cc = "${wasm_cc}"
+			cxx = "${wasm_cxx}"
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+		if [[ "${cross_rust_target}" == *-uefi ]]; then
+			# Profiler is not supported on bare-metal
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				profiler = false
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" bootstrap.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "bootstrap.toml contents:"
+	cat "${S}"/bootstrap.toml || die
+	echo
+}
+
+src_compile() {
+	# -v will show invocations, -vv "very verbose" is overkill, -vvv "very very verbose" is insane
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/bootstrap.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${SLOT}/share/man/
+
+	# bash-completion files are installed by dev-lang/rust-common instead
+	# bug #689562, #689160.
+	rm -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d" || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	if [[ ${PV} = *9999* ]]; then
+		use miri && symlinks+=( miri cargo-miri )
+	fi
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${RUST_PV%%_*}"
+		if [[ -f "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" "${ED}/usr/lib/${PN}/${SLOT}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${SLOT}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${SLOT}/lib" "/usr/lib/${PN}/lib-${SLOT}"
+	use rust-analyzer && dosym "${SLOT}/libexec" "/usr/lib/${PN}/libexec-${SLOT}"
+	dosym "${SLOT}/share/man" "/usr/lib/${PN}/man-${SLOT}"
+	dosym "rust/${SLOT}/lib/rustlib" "/usr/lib/rustlib-${SLOT}"
+	dosym "../../lib/${PN}/${SLOT}/share/doc/rust" "/usr/share/doc/${RUST_P}"
+
+	newenvd - "50${RUST_P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${SLOT}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${PN}-${SLOT}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${RUST_P}"
+	fi
+	if [[ ${SLOT} == *9999* ]] && use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${RUST_P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${RUST_P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${RUST_P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${PN}-${SLOT}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${SLOT}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${RUST_PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.93.0.ebuild b/dev-lang/rust/rust-1.93.0.ebuild
new file mode 100644
index 000000000000..be2ffcad15d4
--- /dev/null
+++ b/dev-lang/rust/rust-1.93.0.ebuild
@@ -0,0 +1,890 @@
+# Copyright 1999-2026 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+# Bump notes: https://wiki.gentoo.org/wiki/Project:Rust/Rust_bump
+
+LLVM_COMPAT=( 21 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+# Patches are kept in rust-patches.git, see its README.rst for the versioning
+# scheme.
+#
+# We use _pN from the ebuild version for the patchset but it can be overridden
+# in the ebuild for changes that don't require a revbump.
+#
+# Uncomment this line when the ebuild needs a patchset update but no revbump.
+#RUST_PATCH_VER=${PV}-1
+
+RUST_MAX_VER=${PV%%_*}
+RUST_PV=${PV%%_p*}
+RUST_P=${PN}-${RUST_PV}
+[[ -z ${RUST_PATCH_VER} ]] && RUST_PATCH_VER=${PV}
+
+if [[ ${PV} == *9999* ]]; then
+	# Update this as new `beta` releases come out.
+	RUST_MIN_VER="1.92.0"
+elif [[ ${PV} == *beta* ]]; then
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+else
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+fi
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature
+inherit multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs
+inherit verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="
+		https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${RUST_PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? (
+			https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+				-> rustc-${RUST_PV}-src.tar.xz.asc
+		)
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${RUST_PV}"
+	SRC_URI="
+		https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+
+	KEYWORDS="~amd64 ~arm ~arm64 ~loong ~mips ~ppc ~ppc64 ~riscv ~sparc ~x86"
+fi
+
+DESCRIPTION="Systems programming language originally developed by Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai )
+ALL_LLVM_TARGETS+=( LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV )
+ALL_LLVM_TARGETS+=( SystemZ VE WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.87.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+# Bare metal targets which can be built on the host system and have no
+# dependency on compiler runtime, libc and unwinder.
+ALL_RUST_SYSROOTS=( bpf wasm )
+ALL_RUST_SYSROOTS=( "${ALL_RUST_SYSROOTS[@]/#/rust_sysroots_}" )
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV%%_*}" # Beta releases get to share the same SLOT as the eventual stable
+
+IUSE="big-endian +clippy cpu_flags_x86_sse2 debug dist +doc llvm-libunwind lto"
+IUSE+=" +rustfmt rust-analyzer rust-src +system-llvm test"
+IUSE+=" ${ALL_LLVM_TARGETS[*]} ${ALL_RUST_SYSROOTS[*]}"
+
+if [[ ${PV} = *9999* ]]; then
+	# These USE flags require nightly rust
+	IUSE+=" miri"
+fi
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	rust_sysroots_wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+# dev-libs/oniguruma is used for documentation
+BDEPEND="
+	${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	dev-libs/oniguruma
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	lto? ( system-llvm? (
+		|| (
+			$(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}')
+			sys-devel/mold
+		)
+	) )
+	rust_sysroots_wasm? ( llvm-core/clang )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="
+	${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="
+	|| ( ${ALL_LLVM_TARGETS[*]} )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	rust_sysroots_bpf? ( llvm_targets_BPF )
+	rust_sysroots_wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${SLOT}/bin/.*
+	usr/lib/${PN}/${SLOT}/libexec/.*
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${SLOT}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	if [[ ${PV} == *9999* ]]; then
+		M=$(( $(usex miri 128 0) + ${M} ))
+	fi
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex rust_sysroots_bpf 256 0) + ${M} ))
+	M=$(( $(usex rust_sysroots_wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+rust_live_get_sources() {
+	EGIT_REPO_URI="
+		https://anongit.gentoo.org/git/proj/rust-patches.git
+	"
+	EGIT_CHECKOUT_DIR="${WORKDIR}/rust-patches-${RUST_PATCH_VER}"
+	git-r3_src_unpack
+
+	EGIT_REPO_URI="
+		https://github.com/rust-lang/rust.git
+	"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+	S="${WORKDIR}/rust"
+	EGIT_CHECKOUT_DIR="${S}"
+	git-r3_src_unpack
+}
+
+src_unpack() {
+	if [[ ${PV} == *9999* ]] ; then
+		rust_live_get_sources
+
+		# Vendor dependencies
+		mkdir "${S}/.cargo" || die # The vendor script has a check for .cargo/config{,.toml}
+		touch "${S}/.cargo/bootstrap.toml" || die
+		local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+		# Configure vendor to use the portage-provided toolchain. This prevents it from
+		# attempting to fetch a `beta` toolchain from the internet.
+		cat <<- _EOF_ > "${T}/vendor-bootstrap.toml"
+			# Suppresses a warning about tracking changes which we don't care about.
+			change-id = "ignore"
+			[build]
+			build = "$(rust_abi "${CBUILD}")"
+			host = ["$(rust_abi "${CHOST}")"]
+			target = ["$(rust_abi "${CHOST}")"]
+			cargo = "${rust_stage0_root}/bin/cargo"
+			rustc = "${rust_stage0_root}/bin/rustc"
+			rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		_EOF_
+		# We're using git sources so we need to run the Vendor script
+		# to ensure that all dependencies are present and up-to-date
+		mkdir "${S}/vendor" || die
+		# This also compiles the 'build helper', there's no way to avoid this.
+		${EPYTHON} "${S}"/x.py vendor -v --config="${T}"/vendor-bootstrap.toml -j$(makeopts_jobs) ||
+			die "Failed to vendor dependencies"
+		# TODO: This has to be generated somehow, this is from a 1.84.x tarball I had lying around.
+		cat <<- _EOF_ > "${S}/.cargo/config.toml"
+			[source.crates-io]
+			replace-with = "vendored-sources"
+
+			[source."git+https://github.com/rust-lang/team"]
+			git = "https://github.com/rust-lang/team"
+			replace-with = "vendored-sources"
+
+			[source.vendored-sources]
+			directory = "vendor"
+		_EOF_
+	elif use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${RUST_PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	if use lto && tc-is-clang && ! tc-ld-is-lld && ! tc-ld-is-mold; then
+		export RUSTFLAGS+=" -C link-arg=-fuse-ld=lld"
+	fi
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	# Avoid bundled copies of libraries
+	export RUSTONIG_SYSTEM_LIBONIG=1
+	# Need to check if these can be optional
+	#export LIBSQLITE3_SYS_USE_PKG_CONFIG=1
+	#export LIBSSH2_SYS_USE_PKG_CONFIG=1
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use rust_sysroots_bpf; then
+		rust_targets+=",\"bpfeb-unknown-none\",\"bpfel-unknown-none\""
+	fi
+	if use rust_sysroots_wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	if [[ ${PV} == *9999* ]]; then
+		use miri && tools+=',"miri"'
+	fi
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	local build_channel
+	local build_miri="false"
+	case "${PV}" in
+		*9999*)
+			build_channel="nightly"
+			;;
+		*beta*)
+			build_channel="beta"
+			;;
+		*)
+			build_channel="stable"
+			;;
+	esac
+
+	# TODO: Add optimized-compiler-builtins for system-llvm to avoid
+	# building bundled compiler-rt.
+	cat <<- _EOF_ > "${S}"/bootstrap.toml
+		# Suppresses a warning about tracking changes which we don't care about.
+		change-id = "ignore"
+		# https://github.com/rust-lang/rust/issues/135358 (bug #947897)
+		profile = "dist"
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		description = "gentoo"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${SLOT}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		channel = "${build_channel}"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		omit-git-hash = false
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex rust_sysroots_wasm))
+		$(if use lto && tc-is-clang && ! tc-ld-is-mold; then
+			echo "use-lld = true"
+		fi)
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex rust_sysroots_wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use rust_sysroots_wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		if tc-is-clang; then
+			local wasm_cc=$(tc-getCC)
+			local wasm_cxx=$(tc-getCXX)
+		else
+			local wasm_cc=${CHOST}-clang
+			local wasm_cxx=${CHOST}-clang++
+		fi
+		export CFLAGS_${wasm_target//-/_}="$(
+			CC="${wasm_cc} --target=wasm32-unknown-unknown"
+			filter-flags '-mcpu*' '-march*' '-mtune*'
+			strip-unsupported-flags
+			echo "${CFLAGS}"
+		)"
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.wasm32-unknown-unknown]
+			cc = "${wasm_cc}"
+			cxx = "${wasm_cxx}"
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+		if [[ "${cross_rust_target}" == *-uefi ]]; then
+			# Profiler is not supported on bare-metal
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				profiler = false
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" bootstrap.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "bootstrap.toml contents:"
+	cat "${S}"/bootstrap.toml || die
+	echo
+}
+
+src_compile() {
+	# -v will show invocations, -vv "very verbose" is overkill, -vvv "very very verbose" is insane
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/bootstrap.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${SLOT}/share/man/
+
+	# bash-completion files are installed by dev-lang/rust-common instead
+	# bug #689562, #689160.
+	rm -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d" || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	if [[ ${PV} = *9999* ]]; then
+		use miri && symlinks+=( miri cargo-miri )
+	fi
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${RUST_PV%%_*}"
+		if [[ -f "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" "${ED}/usr/lib/${PN}/${SLOT}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${SLOT}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${SLOT}/lib" "/usr/lib/${PN}/lib-${SLOT}"
+	use rust-analyzer && dosym "${SLOT}/libexec" "/usr/lib/${PN}/libexec-${SLOT}"
+	dosym "${SLOT}/share/man" "/usr/lib/${PN}/man-${SLOT}"
+	dosym "rust/${SLOT}/lib/rustlib" "/usr/lib/rustlib-${SLOT}"
+	dosym "../../lib/${PN}/${SLOT}/share/doc/rust" "/usr/share/doc/${RUST_P}"
+
+	newenvd - "50${RUST_P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${SLOT}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${PN}-${SLOT}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${RUST_P}"
+	fi
+	if [[ ${SLOT} == *9999* ]] && use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${RUST_P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${RUST_P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${RUST_P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${PN}-${SLOT}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${SLOT}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${RUST_PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.93.1.ebuild b/dev-lang/rust/rust-1.93.1.ebuild
new file mode 100644
index 000000000000..052ef403146e
--- /dev/null
+++ b/dev-lang/rust/rust-1.93.1.ebuild
@@ -0,0 +1,890 @@
+# Copyright 1999-2026 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+# Bump notes: https://wiki.gentoo.org/wiki/Project:Rust/Rust_bump
+
+LLVM_COMPAT=( 21 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+# Patches are kept in rust-patches.git, see its README.rst for the versioning
+# scheme.
+#
+# We use _pN from the ebuild version for the patchset but it can be overridden
+# in the ebuild for changes that don't require a revbump.
+#
+# Uncomment this line when the ebuild needs a patchset update but no revbump.
+#RUST_PATCH_VER=${PV}-1
+
+RUST_MAX_VER=${PV%%_*}
+RUST_PV=${PV%%_p*}
+RUST_P=${PN}-${RUST_PV}
+[[ -z ${RUST_PATCH_VER} ]] && RUST_PATCH_VER=${PV}
+
+if [[ ${PV} == *9999* ]]; then
+	# Update this as new `beta` releases come out.
+	RUST_MIN_VER="1.92.0"
+elif [[ ${PV} == *beta* ]]; then
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+else
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+fi
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature
+inherit multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs
+inherit verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="
+		https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${RUST_PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? (
+			https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+				-> rustc-${RUST_PV}-src.tar.xz.asc
+		)
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${RUST_PV}"
+	SRC_URI="
+		https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~sparc x86"
+fi
+
+DESCRIPTION="Systems programming language originally developed by Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai )
+ALL_LLVM_TARGETS+=( LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV )
+ALL_LLVM_TARGETS+=( SystemZ VE WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.87.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+# Bare metal targets which can be built on the host system and have no
+# dependency on compiler runtime, libc and unwinder.
+ALL_RUST_SYSROOTS=( bpf wasm )
+ALL_RUST_SYSROOTS=( "${ALL_RUST_SYSROOTS[@]/#/rust_sysroots_}" )
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV%%_*}" # Beta releases get to share the same SLOT as the eventual stable
+
+IUSE="big-endian +clippy cpu_flags_x86_sse2 debug dist +doc llvm-libunwind lto"
+IUSE+=" +rustfmt rust-analyzer rust-src +system-llvm test"
+IUSE+=" ${ALL_LLVM_TARGETS[*]} ${ALL_RUST_SYSROOTS[*]}"
+
+if [[ ${PV} = *9999* ]]; then
+	# These USE flags require nightly rust
+	IUSE+=" miri"
+fi
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	rust_sysroots_wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+# dev-libs/oniguruma is used for documentation
+BDEPEND="
+	${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	dev-libs/oniguruma
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	lto? ( system-llvm? (
+		|| (
+			$(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}')
+			sys-devel/mold
+		)
+	) )
+	rust_sysroots_wasm? ( llvm-core/clang )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="
+	${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="
+	|| ( ${ALL_LLVM_TARGETS[*]} )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	rust_sysroots_bpf? ( llvm_targets_BPF )
+	rust_sysroots_wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${SLOT}/bin/.*
+	usr/lib/${PN}/${SLOT}/libexec/.*
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${SLOT}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	if [[ ${PV} == *9999* ]]; then
+		M=$(( $(usex miri 128 0) + ${M} ))
+	fi
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex rust_sysroots_bpf 256 0) + ${M} ))
+	M=$(( $(usex rust_sysroots_wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+rust_live_get_sources() {
+	EGIT_REPO_URI="
+		https://anongit.gentoo.org/git/proj/rust-patches.git
+	"
+	EGIT_CHECKOUT_DIR="${WORKDIR}/rust-patches-${RUST_PATCH_VER}"
+	git-r3_src_unpack
+
+	EGIT_REPO_URI="
+		https://github.com/rust-lang/rust.git
+	"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+	S="${WORKDIR}/rust"
+	EGIT_CHECKOUT_DIR="${S}"
+	git-r3_src_unpack
+}
+
+src_unpack() {
+	if [[ ${PV} == *9999* ]] ; then
+		rust_live_get_sources
+
+		# Vendor dependencies
+		mkdir "${S}/.cargo" || die # The vendor script has a check for .cargo/config{,.toml}
+		touch "${S}/.cargo/bootstrap.toml" || die
+		local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+		# Configure vendor to use the portage-provided toolchain. This prevents it from
+		# attempting to fetch a `beta` toolchain from the internet.
+		cat <<- _EOF_ > "${T}/vendor-bootstrap.toml"
+			# Suppresses a warning about tracking changes which we don't care about.
+			change-id = "ignore"
+			[build]
+			build = "$(rust_abi "${CBUILD}")"
+			host = ["$(rust_abi "${CHOST}")"]
+			target = ["$(rust_abi "${CHOST}")"]
+			cargo = "${rust_stage0_root}/bin/cargo"
+			rustc = "${rust_stage0_root}/bin/rustc"
+			rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		_EOF_
+		# We're using git sources so we need to run the Vendor script
+		# to ensure that all dependencies are present and up-to-date
+		mkdir "${S}/vendor" || die
+		# This also compiles the 'build helper', there's no way to avoid this.
+		${EPYTHON} "${S}"/x.py vendor -v --config="${T}"/vendor-bootstrap.toml -j$(makeopts_jobs) ||
+			die "Failed to vendor dependencies"
+		# TODO: This has to be generated somehow, this is from a 1.84.x tarball I had lying around.
+		cat <<- _EOF_ > "${S}/.cargo/config.toml"
+			[source.crates-io]
+			replace-with = "vendored-sources"
+
+			[source."git+https://github.com/rust-lang/team"]
+			git = "https://github.com/rust-lang/team"
+			replace-with = "vendored-sources"
+
+			[source.vendored-sources]
+			directory = "vendor"
+		_EOF_
+	elif use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${RUST_PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	if use lto && tc-is-clang && ! tc-ld-is-lld && ! tc-ld-is-mold; then
+		export RUSTFLAGS+=" -C link-arg=-fuse-ld=lld"
+	fi
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	# Avoid bundled copies of libraries
+	export RUSTONIG_SYSTEM_LIBONIG=1
+	# Need to check if these can be optional
+	#export LIBSQLITE3_SYS_USE_PKG_CONFIG=1
+	#export LIBSSH2_SYS_USE_PKG_CONFIG=1
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use rust_sysroots_bpf; then
+		rust_targets+=",\"bpfeb-unknown-none\",\"bpfel-unknown-none\""
+	fi
+	if use rust_sysroots_wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	if [[ ${PV} == *9999* ]]; then
+		use miri && tools+=',"miri"'
+	fi
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	local build_channel
+	local build_miri="false"
+	case "${PV}" in
+		*9999*)
+			build_channel="nightly"
+			;;
+		*beta*)
+			build_channel="beta"
+			;;
+		*)
+			build_channel="stable"
+			;;
+	esac
+
+	# TODO: Add optimized-compiler-builtins for system-llvm to avoid
+	# building bundled compiler-rt.
+	cat <<- _EOF_ > "${S}"/bootstrap.toml
+		# Suppresses a warning about tracking changes which we don't care about.
+		change-id = "ignore"
+		# https://github.com/rust-lang/rust/issues/135358 (bug #947897)
+		profile = "dist"
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		description = "gentoo"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${SLOT}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		channel = "${build_channel}"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		omit-git-hash = false
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex rust_sysroots_wasm))
+		$(if use lto && tc-is-clang && ! tc-ld-is-mold; then
+			echo "use-lld = true"
+		fi)
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex rust_sysroots_wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use rust_sysroots_wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		if tc-is-clang; then
+			local wasm_cc=$(tc-getCC)
+			local wasm_cxx=$(tc-getCXX)
+		else
+			local wasm_cc=${CHOST}-clang
+			local wasm_cxx=${CHOST}-clang++
+		fi
+		export CFLAGS_${wasm_target//-/_}="$(
+			CC="${wasm_cc} --target=wasm32-unknown-unknown"
+			filter-flags '-mcpu*' '-march*' '-mtune*'
+			strip-unsupported-flags
+			echo "${CFLAGS}"
+		)"
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.wasm32-unknown-unknown]
+			cc = "${wasm_cc}"
+			cxx = "${wasm_cxx}"
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+		if [[ "${cross_rust_target}" == *-uefi ]]; then
+			# Profiler is not supported on bare-metal
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				profiler = false
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" bootstrap.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "bootstrap.toml contents:"
+	cat "${S}"/bootstrap.toml || die
+	echo
+}
+
+src_compile() {
+	# -v will show invocations, -vv "very verbose" is overkill, -vvv "very very verbose" is insane
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/bootstrap.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${SLOT}/share/man/
+
+	# bash-completion files are installed by dev-lang/rust-common instead
+	# bug #689562, #689160.
+	rm -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d" || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	if [[ ${PV} = *9999* ]]; then
+		use miri && symlinks+=( miri cargo-miri )
+	fi
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${RUST_PV%%_*}"
+		if [[ -f "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" "${ED}/usr/lib/${PN}/${SLOT}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${SLOT}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${SLOT}/lib" "/usr/lib/${PN}/lib-${SLOT}"
+	use rust-analyzer && dosym "${SLOT}/libexec" "/usr/lib/${PN}/libexec-${SLOT}"
+	dosym "${SLOT}/share/man" "/usr/lib/${PN}/man-${SLOT}"
+	dosym "rust/${SLOT}/lib/rustlib" "/usr/lib/rustlib-${SLOT}"
+	dosym "../../lib/${PN}/${SLOT}/share/doc/rust" "/usr/share/doc/${RUST_P}"
+
+	newenvd - "50${RUST_P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${SLOT}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${PN}-${SLOT}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${RUST_P}"
+	fi
+	if [[ ${SLOT} == *9999* ]] && use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${RUST_P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${RUST_P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${RUST_P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${PN}-${SLOT}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${SLOT}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${RUST_PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.94.0.ebuild b/dev-lang/rust/rust-1.94.0.ebuild
new file mode 100644
index 000000000000..2cb5885cda08
--- /dev/null
+++ b/dev-lang/rust/rust-1.94.0.ebuild
@@ -0,0 +1,890 @@
+# Copyright 1999-2026 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+# Bump notes: https://wiki.gentoo.org/wiki/Project:Rust/Rust_bump
+
+LLVM_COMPAT=( 21 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+# Patches are kept in rust-patches.git, see its README.rst for the versioning
+# scheme.
+#
+# We use _pN from the ebuild version for the patchset but it can be overridden
+# in the ebuild for changes that don't require a revbump.
+#
+# Uncomment this line when the ebuild needs a patchset update but no revbump.
+#RUST_PATCH_VER=${PV}-1
+
+RUST_MAX_VER=${PV%%_*}
+RUST_PV=${PV%%_p*}
+RUST_P=${PN}-${RUST_PV}
+[[ -z ${RUST_PATCH_VER} ]] && RUST_PATCH_VER=${PV}
+
+if [[ ${PV} == *9999* ]]; then
+	# Update this as new `beta` releases come out.
+	RUST_MIN_VER="1.93.0"
+elif [[ ${PV} == *beta* ]]; then
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+else
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+fi
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature
+inherit multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs
+inherit verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="
+		https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${RUST_PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? (
+			https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+				-> rustc-${RUST_PV}-src.tar.xz.asc
+		)
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${RUST_PV}"
+	SRC_URI="
+		https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+
+	KEYWORDS="~amd64 ~arm ~arm64 ~loong ~mips ~ppc ~ppc64 ~riscv ~sparc ~x86"
+fi
+
+DESCRIPTION="Systems programming language originally developed by Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai )
+ALL_LLVM_TARGETS+=( LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV )
+ALL_LLVM_TARGETS+=( SystemZ VE WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.87.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+# Bare metal targets which can be built on the host system and have no
+# dependency on compiler runtime, libc and unwinder.
+ALL_RUST_SYSROOTS=( bpf wasm )
+ALL_RUST_SYSROOTS=( "${ALL_RUST_SYSROOTS[@]/#/rust_sysroots_}" )
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV%%_*}" # Beta releases get to share the same SLOT as the eventual stable
+
+IUSE="big-endian +clippy cpu_flags_x86_sse2 debug dist +doc llvm-libunwind lto"
+IUSE+=" +rustfmt rust-analyzer rust-src +system-llvm test"
+IUSE+=" ${ALL_LLVM_TARGETS[*]} ${ALL_RUST_SYSROOTS[*]}"
+
+if [[ ${PV} = *9999* ]]; then
+	# These USE flags require nightly rust
+	IUSE+=" miri"
+fi
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	rust_sysroots_wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+# dev-libs/oniguruma is used for documentation
+BDEPEND="
+	${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	dev-libs/oniguruma
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	lto? ( system-llvm? (
+		|| (
+			$(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}')
+			sys-devel/mold
+		)
+	) )
+	rust_sysroots_wasm? ( llvm-core/clang )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="
+	${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="
+	|| ( ${ALL_LLVM_TARGETS[*]} )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	rust_sysroots_bpf? ( llvm_targets_BPF )
+	rust_sysroots_wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${SLOT}/bin/.*
+	usr/lib/${PN}/${SLOT}/libexec/.*
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${SLOT}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	if [[ ${PV} == *9999* ]]; then
+		M=$(( $(usex miri 128 0) + ${M} ))
+	fi
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex rust_sysroots_bpf 256 0) + ${M} ))
+	M=$(( $(usex rust_sysroots_wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+rust_live_get_sources() {
+	EGIT_REPO_URI="
+		https://anongit.gentoo.org/git/proj/rust-patches.git
+	"
+	EGIT_CHECKOUT_DIR="${WORKDIR}/rust-patches-${RUST_PATCH_VER}"
+	git-r3_src_unpack
+
+	EGIT_REPO_URI="
+		https://github.com/rust-lang/rust.git
+	"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+	S="${WORKDIR}/rust"
+	EGIT_CHECKOUT_DIR="${S}"
+	git-r3_src_unpack
+}
+
+src_unpack() {
+	if [[ ${PV} == *9999* ]] ; then
+		rust_live_get_sources
+
+		# Vendor dependencies
+		mkdir "${S}/.cargo" || die # The vendor script has a check for .cargo/config{,.toml}
+		touch "${S}/.cargo/bootstrap.toml" || die
+		local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+		# Configure vendor to use the portage-provided toolchain. This prevents it from
+		# attempting to fetch a `beta` toolchain from the internet.
+		cat <<- _EOF_ > "${T}/vendor-bootstrap.toml"
+			# Suppresses a warning about tracking changes which we don't care about.
+			change-id = "ignore"
+			[build]
+			build = "$(rust_abi "${CBUILD}")"
+			host = ["$(rust_abi "${CHOST}")"]
+			target = ["$(rust_abi "${CHOST}")"]
+			cargo = "${rust_stage0_root}/bin/cargo"
+			rustc = "${rust_stage0_root}/bin/rustc"
+			rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		_EOF_
+		# We're using git sources so we need to run the Vendor script
+		# to ensure that all dependencies are present and up-to-date
+		mkdir "${S}/vendor" || die
+		# This also compiles the 'build helper', there's no way to avoid this.
+		${EPYTHON} "${S}"/x.py vendor -v --config="${T}"/vendor-bootstrap.toml -j$(makeopts_jobs) ||
+			die "Failed to vendor dependencies"
+		# TODO: This has to be generated somehow, this is from a 1.84.x tarball I had lying around.
+		cat <<- _EOF_ > "${S}/.cargo/config.toml"
+			[source.crates-io]
+			replace-with = "vendored-sources"
+
+			[source."git+https://github.com/rust-lang/team"]
+			git = "https://github.com/rust-lang/team"
+			replace-with = "vendored-sources"
+
+			[source.vendored-sources]
+			directory = "vendor"
+		_EOF_
+	elif use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${RUST_PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	if use lto && tc-is-clang && ! tc-ld-is-lld && ! tc-ld-is-mold; then
+		export RUSTFLAGS+=" -C link-arg=-fuse-ld=lld"
+	fi
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	# Avoid bundled copies of libraries
+	export RUSTONIG_SYSTEM_LIBONIG=1
+	# Need to check if these can be optional
+	#export LIBSQLITE3_SYS_USE_PKG_CONFIG=1
+	#export LIBSSH2_SYS_USE_PKG_CONFIG=1
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use rust_sysroots_bpf; then
+		rust_targets+=",\"bpfeb-unknown-none\",\"bpfel-unknown-none\""
+	fi
+	if use rust_sysroots_wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	if [[ ${PV} == *9999* ]]; then
+		use miri && tools+=',"miri"'
+	fi
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	local build_channel
+	local build_miri="false"
+	case "${PV}" in
+		*9999*)
+			build_channel="nightly"
+			;;
+		*beta*)
+			build_channel="beta"
+			;;
+		*)
+			build_channel="stable"
+			;;
+	esac
+
+	# TODO: Add optimized-compiler-builtins for system-llvm to avoid
+	# building bundled compiler-rt.
+	cat <<- _EOF_ > "${S}"/bootstrap.toml
+		# Suppresses a warning about tracking changes which we don't care about.
+		change-id = "ignore"
+		# https://github.com/rust-lang/rust/issues/135358 (bug #947897)
+		profile = "dist"
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		description = "gentoo"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${SLOT}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		channel = "${build_channel}"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		omit-git-hash = false
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex rust_sysroots_wasm))
+		$(if use lto && tc-is-clang && ! tc-ld-is-mold; then
+			echo "use-lld = true"
+		fi)
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex rust_sysroots_wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use rust_sysroots_wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		if tc-is-clang; then
+			local wasm_cc=$(tc-getCC)
+			local wasm_cxx=$(tc-getCXX)
+		else
+			local wasm_cc=${CHOST}-clang
+			local wasm_cxx=${CHOST}-clang++
+		fi
+		export CFLAGS_${wasm_target//-/_}="$(
+			CC="${wasm_cc} --target=wasm32-unknown-unknown"
+			filter-flags '-mcpu*' '-march*' '-mtune*'
+			strip-unsupported-flags
+			echo "${CFLAGS}"
+		)"
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.wasm32-unknown-unknown]
+			cc = "${wasm_cc}"
+			cxx = "${wasm_cxx}"
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+		if [[ "${cross_rust_target}" == *-uefi ]]; then
+			# Profiler is not supported on bare-metal
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				profiler = false
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" bootstrap.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "bootstrap.toml contents:"
+	cat "${S}"/bootstrap.toml || die
+	echo
+}
+
+src_compile() {
+	# -v will show invocations, -vv "very verbose" is overkill, -vvv "very very verbose" is insane
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/bootstrap.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${SLOT}/share/man/
+
+	# bash-completion files are installed by dev-lang/rust-common instead
+	# bug #689562, #689160.
+	rm -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d" || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	if [[ ${PV} = *9999* ]]; then
+		use miri && symlinks+=( miri cargo-miri )
+	fi
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${RUST_PV%%_*}"
+		if [[ -f "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" "${ED}/usr/lib/${PN}/${SLOT}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${SLOT}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${SLOT}/lib" "/usr/lib/${PN}/lib-${SLOT}"
+	use rust-analyzer && dosym "${SLOT}/libexec" "/usr/lib/${PN}/libexec-${SLOT}"
+	dosym "${SLOT}/share/man" "/usr/lib/${PN}/man-${SLOT}"
+	dosym "rust/${SLOT}/lib/rustlib" "/usr/lib/rustlib-${SLOT}"
+	dosym "../../lib/${PN}/${SLOT}/share/doc/rust" "/usr/share/doc/${RUST_P}"
+
+	newenvd - "50${RUST_P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${SLOT}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${PN}-${SLOT}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${RUST_P}"
+	fi
+	if [[ ${SLOT} == *9999* ]] && use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${RUST_P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${RUST_P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${RUST_P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${PN}-${SLOT}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/bootstrap.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${SLOT}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${RUST_PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.94.1.ebuild b/dev-lang/rust/rust-1.94.1.ebuild
new file mode 100644
index 000000000000..50d916b0ba06
--- /dev/null
+++ b/dev-lang/rust/rust-1.94.1.ebuild
@@ -0,0 +1,900 @@
+# Copyright 1999-2026 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+# Bump notes: https://wiki.gentoo.org/wiki/Project:Rust/Rust_bump
+
+LLVM_COMPAT=( 21 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+# Patches are kept in rust-patches.git, see its README.rst for the versioning
+# scheme.
+#
+# We use _pN from the ebuild version for the patchset but it can be overridden
+# in the ebuild for changes that don't require a revbump.
+#
+# Uncomment this line when the ebuild needs a patchset update but no revbump.
+# RUST_PATCH_VER=${PV}-1
+
+RUST_MAX_VER=${PV%%_*}
+RUST_PV=${PV%%_p*}
+RUST_P=${PN}-${RUST_PV}
+[[ -z ${RUST_PATCH_VER} ]] && RUST_PATCH_VER=${PV}
+
+if [[ ${PV} == *9999* ]]; then
+	# Update this as new `beta` releases come out.
+	RUST_MIN_VER="1.93.0"
+elif [[ ${PV} == *beta* ]]; then
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+else
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+fi
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature
+inherit multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs
+inherit verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="
+		https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${RUST_PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? (
+			https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+				-> rustc-${RUST_PV}-src.tar.xz.asc
+		)
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${RUST_PV}"
+	SRC_URI="
+		https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+
+	KEYWORDS="~amd64 ~arm ~arm64 ~loong ~mips ~ppc ~ppc64 ~riscv ~sparc ~x86"
+fi
+
+DESCRIPTION="Systems programming language originally developed by Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai )
+ALL_LLVM_TARGETS+=( LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV )
+ALL_LLVM_TARGETS+=( SystemZ VE WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.87.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+# Bare metal targets which can be built on the host system and have no
+# dependency on compiler runtime, libc and unwinder.
+ALL_RUST_SYSROOTS=( bpf wasm )
+ALL_RUST_SYSROOTS=( "${ALL_RUST_SYSROOTS[@]/#/rust_sysroots_}" )
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV%%_*}" # Beta releases get to share the same SLOT as the eventual stable
+
+IUSE="big-endian +clippy cpu_flags_x86_sse2 debug dist +doc llvm-libunwind lto"
+IUSE+=" +rustfmt rust-analyzer rust-src +system-llvm test"
+IUSE+=" ${ALL_LLVM_TARGETS[*]} ${ALL_RUST_SYSROOTS[*]}"
+
+if [[ ${PV} = *9999* ]]; then
+	# These USE flags require nightly rust
+	IUSE+=" miri"
+fi
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	rust_sysroots_wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+# dev-libs/oniguruma is used for documentation
+BDEPEND="
+	${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	dev-libs/oniguruma
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	lto? ( system-llvm? (
+		|| (
+			$(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}')
+			sys-devel/mold
+		)
+	) )
+	rust_sysroots_wasm? ( llvm-core/clang )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	dev-db/sqlite:3
+	net-misc/curl[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="
+	${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="
+	|| ( ${ALL_LLVM_TARGETS[*]} )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	rust_sysroots_bpf? ( llvm_targets_BPF )
+	rust_sysroots_wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${SLOT}/bin/.*
+	usr/lib/${PN}/${SLOT}/libexec/.*
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/rust-objcopy
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${SLOT}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	if [[ ${PV} == *9999* ]]; then
+		M=$(( $(usex miri 128 0) + ${M} ))
+	fi
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex rust_sysroots_bpf 256 0) + ${M} ))
+	M=$(( $(usex rust_sysroots_wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+rust_live_get_sources() {
+	EGIT_REPO_URI="
+		https://anongit.gentoo.org/git/proj/rust-patches.git
+	"
+	EGIT_CHECKOUT_DIR="${WORKDIR}/rust-patches-${RUST_PATCH_VER}"
+	git-r3_src_unpack
+
+	EGIT_REPO_URI="
+		https://github.com/rust-lang/rust.git
+	"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+	S="${WORKDIR}/rust"
+	EGIT_CHECKOUT_DIR="${S}"
+	git-r3_src_unpack
+}
+
+src_unpack() {
+	if [[ ${PV} == *9999* ]] ; then
+		rust_live_get_sources
+
+		# Vendor dependencies
+		mkdir "${S}/.cargo" || die # The vendor script has a check for .cargo/config{,.toml}
+		touch "${S}/.cargo/bootstrap.toml" || die
+		local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+		# Configure vendor to use the portage-provided toolchain. This prevents it from
+		# attempting to fetch a `beta` toolchain from the internet.
+		cat <<- _EOF_ > "${T}/vendor-bootstrap.toml"
+			# Suppresses a warning about tracking changes which we don't care about.
+			change-id = "ignore"
+			[build]
+			build = "$(rust_abi "${CBUILD}")"
+			host = ["$(rust_abi "${CHOST}")"]
+			target = ["$(rust_abi "${CHOST}")"]
+			cargo = "${rust_stage0_root}/bin/cargo"
+			rustc = "${rust_stage0_root}/bin/rustc"
+			rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		_EOF_
+		# We're using git sources so we need to run the Vendor script
+		# to ensure that all dependencies are present and up-to-date
+		mkdir "${S}/vendor" || die
+		# This also compiles the 'build helper', there's no way to avoid this.
+		${EPYTHON} "${S}"/x.py vendor -v --config="${T}"/vendor-bootstrap.toml \
+			-j$(get_makeopts_jobs) ||
+				die "Failed to vendor dependencies"
+		# TODO: This has to be generated somehow, this is from a 1.84.x tarball I had lying around.
+		cat <<- _EOF_ > "${S}/.cargo/config.toml"
+			[source.crates-io]
+			replace-with = "vendored-sources"
+
+			[source."git+https://github.com/rust-lang/team"]
+			git = "https://github.com/rust-lang/team"
+			replace-with = "vendored-sources"
+
+			[source.vendored-sources]
+			directory = "vendor"
+		_EOF_
+	elif use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${RUST_PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	if use lto && tc-is-clang && ! tc-ld-is-lld && ! tc-ld-is-mold; then
+		export RUSTFLAGS+=" -C link-arg=-fuse-ld=lld"
+	fi
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	# Avoid bundled copies of libraries
+	export RUSTONIG_SYSTEM_LIBONIG=1
+	export LIBSQLITE3_SYS_USE_PKG_CONFIG=1
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use rust_sysroots_bpf; then
+		rust_targets+=",\"bpfeb-unknown-none\",\"bpfel-unknown-none\""
+	fi
+	if use rust_sysroots_wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	if [[ ${PV} == *9999* ]]; then
+		use miri && tools+=',"miri"'
+	fi
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	local build_channel
+	local build_miri="false"
+	case "${PV}" in
+		*9999*)
+			build_channel="nightly"
+			;;
+		*beta*)
+			build_channel="beta"
+			;;
+		*)
+			build_channel="stable"
+			;;
+	esac
+
+	# TODO: Add optimized-compiler-builtins for system-llvm to avoid
+	# building bundled compiler-rt.
+	cat <<- _EOF_ > "${S}"/bootstrap.toml
+		# Suppresses a warning about tracking changes which we don't care about.
+		change-id = "ignore"
+		# https://github.com/rust-lang/rust/issues/135358 (bug #947897)
+		profile = "dist"
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		description = "gentoo"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${SLOT}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		channel = "${build_channel}"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		omit-git-hash = false
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex rust_sysroots_wasm))
+		$(if use lto && tc-is-clang && ! tc-ld-is-mold; then
+			echo "use-lld = true"
+		fi)
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex rust_sysroots_wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use rust_sysroots_wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		if tc-is-clang; then
+			local wasm_cc=$(tc-getCC)
+			local wasm_cxx=$(tc-getCXX)
+		else
+			local wasm_cc=${CHOST}-clang
+			local wasm_cxx=${CHOST}-clang++
+		fi
+		export CFLAGS_${wasm_target//-/_}="$(
+			CC="${wasm_cc} --target=wasm32-unknown-unknown"
+			filter-flags '-mcpu*' '-march*' '-mtune*'
+			strip-unsupported-flags
+			echo "${CFLAGS}"
+		)"
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.wasm32-unknown-unknown]
+			cc = "${wasm_cc}"
+			cxx = "${wasm_cxx}"
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+		if [[ "${cross_rust_target}" == *-uefi ]]; then
+			# Profiler is not supported on bare-metal
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				profiler = false
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" bootstrap.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "bootstrap.toml contents:"
+	cat "${S}"/bootstrap.toml || die
+	echo
+}
+
+src_compile() {
+	# -v will show invocations, -vv "very verbose" is overkill, -vvv "very very verbose" is insane
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v \
+		--config="${S}"/bootstrap.toml -j$(get_makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen-units
+		codegen-llvm
+		crashes
+		incremental
+		mir-opt
+		pretty
+		run-make
+		run-make-cargo
+	)
+
+	# tests for standard and core library
+	local std_tests=(
+		std
+		core
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly-llvm )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]} ${std_tests[@]}"
+	for i in "tests/${tests[@]}" "library/${std_tests[@]}"; do
+		local t="${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/bootstrap.toml \
+				-j$(get_makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v \
+		--config="${S}"/bootstrap.toml -j$(get_makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${SLOT}/share/man/
+
+	# bash-completion files are installed by dev-lang/rust-common instead
+	# bug #689562, #689160.
+	rm -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d" || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	if [[ ${PV} = *9999* ]]; then
+		use miri && symlinks+=( miri cargo-miri )
+	fi
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${RUST_PV%%_*}"
+		if [[ -f "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" "${ED}/usr/lib/${PN}/${SLOT}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${SLOT}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${SLOT}/lib" "/usr/lib/${PN}/lib-${SLOT}"
+	use rust-analyzer && dosym "${SLOT}/libexec" "/usr/lib/${PN}/libexec-${SLOT}"
+	dosym "${SLOT}/share/man" "/usr/lib/${PN}/man-${SLOT}"
+	dosym "rust/${SLOT}/lib/rustlib" "/usr/lib/rustlib-${SLOT}"
+	dosym "../../lib/${PN}/${SLOT}/share/doc/rust" "/usr/share/doc/${RUST_P}"
+
+	newenvd - "50${RUST_P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${SLOT}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${PN}-${SLOT}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${RUST_P}"
+	fi
+	if [[ ${SLOT} == *9999* ]] && use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${RUST_P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${RUST_P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${RUST_P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${PN}-${SLOT}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/bootstrap.toml \
+			-j$(get_makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${SLOT}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${RUST_PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.95.0.ebuild b/dev-lang/rust/rust-1.95.0.ebuild
new file mode 100644
index 000000000000..df9c0019e31a
--- /dev/null
+++ b/dev-lang/rust/rust-1.95.0.ebuild
@@ -0,0 +1,900 @@
+# Copyright 1999-2026 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+# Bump notes: https://wiki.gentoo.org/wiki/Project:Rust/Rust_bump
+
+LLVM_COMPAT=( 22 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+# Patches are kept in rust-patches.git, see its README.rst for the versioning
+# scheme.
+#
+# We use _pN from the ebuild version for the patchset but it can be overridden
+# in the ebuild for changes that don't require a revbump.
+#
+# Uncomment this line when the ebuild needs a patchset update but no revbump.
+# RUST_PATCH_VER=${PV}-1
+
+RUST_MAX_VER=${PV%%_*}
+RUST_PV=${PV%%_p*}
+RUST_P=${PN}-${RUST_PV}
+[[ -z ${RUST_PATCH_VER} ]] && RUST_PATCH_VER=${PV}
+
+if [[ ${PV} == *9999* ]]; then
+	# Update this as new `beta` releases come out.
+	RUST_MIN_VER="1.93.0"
+elif [[ ${PV} == *beta* ]]; then
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+else
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+fi
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature
+inherit multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs
+inherit verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="
+		https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${RUST_PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? (
+			https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+				-> rustc-${RUST_PV}-src.tar.xz.asc
+		)
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${RUST_PV}"
+	SRC_URI="
+		https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+
+	KEYWORDS="~amd64 ~arm ~arm64 ~loong ~mips ~ppc ~ppc64 ~riscv ~sparc ~x86"
+fi
+
+DESCRIPTION="Systems programming language originally developed by Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai )
+ALL_LLVM_TARGETS+=( LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV )
+ALL_LLVM_TARGETS+=( SystemZ VE WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.87.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+# Bare metal targets which can be built on the host system and have no
+# dependency on compiler runtime, libc and unwinder.
+ALL_RUST_SYSROOTS=( bpf wasm )
+ALL_RUST_SYSROOTS=( "${ALL_RUST_SYSROOTS[@]/#/rust_sysroots_}" )
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV%%_*}" # Beta releases get to share the same SLOT as the eventual stable
+
+IUSE="big-endian +clippy cpu_flags_x86_sse2 debug dist +doc llvm-libunwind lto"
+IUSE+=" +rustfmt rust-analyzer rust-src +system-llvm test"
+IUSE+=" ${ALL_LLVM_TARGETS[*]} ${ALL_RUST_SYSROOTS[*]}"
+
+if [[ ${PV} = *9999* ]]; then
+	# These USE flags require nightly rust
+	IUSE+=" miri"
+fi
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	rust_sysroots_wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+# dev-libs/oniguruma is used for documentation
+BDEPEND="
+	${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	dev-libs/oniguruma
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	lto? ( system-llvm? (
+		|| (
+			$(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}')
+			sys-devel/mold
+		)
+	) )
+	rust_sysroots_wasm? ( llvm-core/clang )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	dev-db/sqlite:3
+	net-misc/curl[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="
+	${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="
+	|| ( ${ALL_LLVM_TARGETS[*]} )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	rust_sysroots_bpf? ( llvm_targets_BPF )
+	rust_sysroots_wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${SLOT}/bin/.*
+	usr/lib/${PN}/${SLOT}/libexec/.*
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/rust-objcopy
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${SLOT}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	if [[ ${PV} == *9999* ]]; then
+		M=$(( $(usex miri 128 0) + ${M} ))
+	fi
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex rust_sysroots_bpf 256 0) + ${M} ))
+	M=$(( $(usex rust_sysroots_wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+rust_live_get_sources() {
+	EGIT_REPO_URI="
+		https://anongit.gentoo.org/git/proj/rust-patches.git
+	"
+	EGIT_CHECKOUT_DIR="${WORKDIR}/rust-patches-${RUST_PATCH_VER}"
+	git-r3_src_unpack
+
+	EGIT_REPO_URI="
+		https://github.com/rust-lang/rust.git
+	"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+	S="${WORKDIR}/rust"
+	EGIT_CHECKOUT_DIR="${S}"
+	git-r3_src_unpack
+}
+
+src_unpack() {
+	if [[ ${PV} == *9999* ]] ; then
+		rust_live_get_sources
+
+		# Vendor dependencies
+		mkdir "${S}/.cargo" || die # The vendor script has a check for .cargo/config{,.toml}
+		touch "${S}/.cargo/bootstrap.toml" || die
+		local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+		# Configure vendor to use the portage-provided toolchain. This prevents it from
+		# attempting to fetch a `beta` toolchain from the internet.
+		cat <<- _EOF_ > "${T}/vendor-bootstrap.toml"
+			# Suppresses a warning about tracking changes which we don't care about.
+			change-id = "ignore"
+			[build]
+			build = "$(rust_abi "${CBUILD}")"
+			host = ["$(rust_abi "${CHOST}")"]
+			target = ["$(rust_abi "${CHOST}")"]
+			cargo = "${rust_stage0_root}/bin/cargo"
+			rustc = "${rust_stage0_root}/bin/rustc"
+			rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		_EOF_
+		# We're using git sources so we need to run the Vendor script
+		# to ensure that all dependencies are present and up-to-date
+		mkdir "${S}/vendor" || die
+		# This also compiles the 'build helper', there's no way to avoid this.
+		${EPYTHON} "${S}"/x.py vendor -v --config="${T}"/vendor-bootstrap.toml \
+			-j$(get_makeopts_jobs) ||
+				die "Failed to vendor dependencies"
+		# TODO: This has to be generated somehow, this is from a 1.84.x tarball I had lying around.
+		cat <<- _EOF_ > "${S}/.cargo/config.toml"
+			[source.crates-io]
+			replace-with = "vendored-sources"
+
+			[source."git+https://github.com/rust-lang/team"]
+			git = "https://github.com/rust-lang/team"
+			replace-with = "vendored-sources"
+
+			[source.vendored-sources]
+			directory = "vendor"
+		_EOF_
+	elif use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${RUST_PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	if use lto && tc-is-clang && ! tc-ld-is-lld && ! tc-ld-is-mold; then
+		export RUSTFLAGS+=" -C link-arg=-fuse-ld=lld"
+	fi
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	# Avoid bundled copies of libraries
+	export RUSTONIG_SYSTEM_LIBONIG=1
+	export LIBSQLITE3_SYS_USE_PKG_CONFIG=1
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use rust_sysroots_bpf; then
+		rust_targets+=",\"bpfeb-unknown-none\",\"bpfel-unknown-none\""
+	fi
+	if use rust_sysroots_wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	if [[ ${PV} == *9999* ]]; then
+		use miri && tools+=',"miri"'
+	fi
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	local build_channel
+	local build_miri="false"
+	case "${PV}" in
+		*9999*)
+			build_channel="nightly"
+			;;
+		*beta*)
+			build_channel="beta"
+			;;
+		*)
+			build_channel="stable"
+			;;
+	esac
+
+	# TODO: Add optimized-compiler-builtins for system-llvm to avoid
+	# building bundled compiler-rt.
+	cat <<- _EOF_ > "${S}"/bootstrap.toml
+		# Suppresses a warning about tracking changes which we don't care about.
+		change-id = "ignore"
+		# https://github.com/rust-lang/rust/issues/135358 (bug #947897)
+		profile = "dist"
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		description = "gentoo"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${SLOT}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		channel = "${build_channel}"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		omit-git-hash = false
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex rust_sysroots_wasm))
+		$(if use lto && tc-is-clang && ! tc-ld-is-mold; then
+			echo "use-lld = true"
+		fi)
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex rust_sysroots_wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use rust_sysroots_wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		if tc-is-clang; then
+			local wasm_cc=$(tc-getCC)
+			local wasm_cxx=$(tc-getCXX)
+		else
+			local wasm_cc=${CHOST}-clang
+			local wasm_cxx=${CHOST}-clang++
+		fi
+		export CFLAGS_${wasm_target//-/_}="$(
+			CC="${wasm_cc} --target=wasm32-unknown-unknown"
+			filter-flags '-mcpu*' '-march*' '-mtune*'
+			strip-unsupported-flags
+			echo "${CFLAGS}"
+		)"
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.wasm32-unknown-unknown]
+			cc = "${wasm_cc}"
+			cxx = "${wasm_cxx}"
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+		if [[ "${cross_rust_target}" == *-uefi ]]; then
+			# Profiler is not supported on bare-metal
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				profiler = false
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" bootstrap.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "bootstrap.toml contents:"
+	cat "${S}"/bootstrap.toml || die
+	echo
+}
+
+src_compile() {
+	# -v will show invocations, -vv "very verbose" is overkill, -vvv "very very verbose" is insane
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v \
+		--config="${S}"/bootstrap.toml -j$(get_makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen-units
+		crashes
+		codegen-llvm
+		incremental
+		mir-opt
+		pretty
+		run-make
+		run-make-cargo
+	)
+
+	# tests for standard and core library
+	local std_tests=(
+		std
+		core
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly-llvm )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]} ${std_tests[@]}"
+	for i in "tests/${tests[@]}" "library/${std_tests[@]}"; do
+		local t="${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/bootstrap.toml \
+				-j$(get_makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v \
+		--config="${S}"/bootstrap.toml -j$(get_makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${SLOT}/share/man/
+
+	# bash-completion files are installed by dev-lang/rust-common instead
+	# bug #689562, #689160.
+	rm -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d" || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	if [[ ${PV} = *9999* ]]; then
+		use miri && symlinks+=( miri cargo-miri )
+	fi
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${RUST_PV%%_*}"
+		if [[ -f "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" "${ED}/usr/lib/${PN}/${SLOT}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${SLOT}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${SLOT}/lib" "/usr/lib/${PN}/lib-${SLOT}"
+	use rust-analyzer && dosym "${SLOT}/libexec" "/usr/lib/${PN}/libexec-${SLOT}"
+	dosym "${SLOT}/share/man" "/usr/lib/${PN}/man-${SLOT}"
+	dosym "rust/${SLOT}/lib/rustlib" "/usr/lib/rustlib-${SLOT}"
+	dosym "../../lib/${PN}/${SLOT}/share/doc/rust" "/usr/share/doc/${RUST_P}"
+
+	newenvd - "50${RUST_P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${SLOT}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${PN}-${SLOT}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${RUST_P}"
+	fi
+	if [[ ${SLOT} == *9999* ]] && use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${RUST_P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${RUST_P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${RUST_P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${PN}-${SLOT}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/bootstrap.toml \
+			-j$(get_makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${SLOT}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${RUST_PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-9999.ebuild b/dev-lang/rust/rust-9999.ebuild
new file mode 100644
index 000000000000..d46fcd1af24e
--- /dev/null
+++ b/dev-lang/rust/rust-9999.ebuild
@@ -0,0 +1,900 @@
+# Copyright 1999-2026 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+# Bump notes: https://wiki.gentoo.org/wiki/Project:Rust/Rust_bump
+
+LLVM_COMPAT=( 22 )
+PYTHON_COMPAT=( python3_{13..14} )
+
+# Patches are kept in rust-patches.git, see its README.rst for the versioning
+# scheme.
+#
+# We use _pN from the ebuild version for the patchset but it can be overridden
+# in the ebuild for changes that don't require a revbump.
+#
+# Uncomment this line when the ebuild needs a patchset update but no revbump.
+# RUST_PATCH_VER=${PV}-1
+
+RUST_MAX_VER=${PV%%_*}
+RUST_PV=${PV%%_p*}
+RUST_P=${PN}-${RUST_PV}
+[[ -z ${RUST_PATCH_VER} ]] && RUST_PATCH_VER=${PV}
+
+if [[ ${PV} == *9999* ]]; then
+	# Update this as new `beta` releases come out.
+	RUST_MIN_VER="1.94.0"
+elif [[ ${PV} == *beta* ]]; then
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+else
+	RUST_MIN_VER="$(ver_cut 1).$(($(ver_cut 2) - 1)).0"
+fi
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature
+inherit multilib multilib-build python-any-r1 rust rust-toolchain toolchain-funcs
+inherit verify-sig
+
+if [[ ${PV} = *9999* ]]; then
+	inherit git-r3
+elif [[ ${PV} == *beta* ]]; then
+	# Identify the snapshot date of the beta release:
+	# curl -Ls static.rust-lang.org/dist/channel-rust-beta.toml | grep beta-src.tar.xz
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC_URI="
+		https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${RUST_PV}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? (
+			https://static.rust-lang.org/dist/${BETA_SNAPSHOT}/rustc-beta-src.tar.xz.asc
+				-> rustc-${RUST_PV}-src.tar.xz.asc
+		)
+	"
+	S="${WORKDIR}/${MY_P}-src"
+else
+	MY_P="rustc-${RUST_PV}"
+	SRC_URI="
+		https://static.rust-lang.org/dist/${MY_P}-src.tar.xz
+		https://gitweb.gentoo.org/proj/rust-patches.git/snapshot/rust-patches-${RUST_PATCH_VER}.tar.bz2
+		verify-sig? ( https://static.rust-lang.org/dist/${MY_P}-src.tar.xz.asc )
+	"
+	S="${WORKDIR}/${MY_P}-src"
+
+	KEYWORDS="~amd64 ~arm ~arm64 ~loong ~mips ~ppc ~ppc64 ~riscv ~sparc ~x86"
+fi
+
+DESCRIPTION="Systems programming language originally developed by Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai )
+ALL_LLVM_TARGETS+=( LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV )
+ALL_LLVM_TARGETS+=( SystemZ VE WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+# https://github.com/rust-lang/llvm-project/blob/rustc-1.87.0/llvm/CMakeLists.txt
+_ALL_RUST_EXPERIMENTAL_TARGETS=( ARC CSKY DirectX M68k Xtensa )
+declare -A ALL_RUST_EXPERIMENTAL_TARGETS
+for _x in "${_ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+	ALL_RUST_EXPERIMENTAL_TARGETS["llvm_targets_${_x}"]=0
+done
+
+# Bare metal targets which can be built on the host system and have no
+# dependency on compiler runtime, libc and unwinder.
+ALL_RUST_SYSROOTS=( bpf wasm )
+ALL_RUST_SYSROOTS=( "${ALL_RUST_SYSROOTS[@]/#/rust_sysroots_}" )
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV%%_*}" # Beta releases get to share the same SLOT as the eventual stable
+
+IUSE="big-endian +clippy cpu_flags_x86_sse2 debug dist +doc llvm-libunwind lto"
+IUSE+=" +rustfmt rust-analyzer rust-src +system-llvm test"
+IUSE+=" ${ALL_LLVM_TARGETS[*]} ${ALL_RUST_SYSROOTS[*]}"
+
+if [[ ${PV} = *9999* ]]; then
+	# These USE flags require nightly rust
+	IUSE+=" miri"
+fi
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "llvm-core/llvm:\${LLVM_SLOT}[${_x}=]") )" )
+	if [[ -v ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"] ]] ; then
+		ALL_RUST_EXPERIMENTAL_TARGETS["${_x}"]=1
+	fi
+done
+LLVM_DEPEND+=( "	rust_sysroots_wasm? ( $(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'llvm-core/llvm:${LLVM_SLOT}')" )
+
+# dev-libs/oniguruma is used for documentation
+BDEPEND="
+	${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	dev-libs/oniguruma
+	|| (
+		>=sys-devel/gcc-4.7[cxx]
+		>=llvm-core/clang-3.5
+	)
+	lto? ( system-llvm? (
+		|| (
+			$(llvm_gen_dep 'llvm-core/lld:${LLVM_SLOT}')
+			sys-devel/mold
+		)
+	) )
+	rust_sysroots_wasm? ( llvm-core/clang )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	dev-db/sqlite:3
+	net-misc/curl[http2,ssl]
+	virtual/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND[*]}
+		llvm-libunwind? ( llvm-runtimes/libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="
+	${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable
+	!dev-lang/rust-bin:stable
+"
+
+REQUIRED_USE="
+	|| ( ${ALL_LLVM_TARGETS[*]} )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	rust_sysroots_bpf? ( llvm_targets_BPF )
+	rust_sysroots_wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${SLOT}/bin/.*
+	usr/lib/${PN}/${SLOT}/libexec/.*
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${SLOT}/lib/lib.*.so.*
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/bin/rust-objcopy
+	usr/lib/${PN}/${SLOT}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${SLOT}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+pre_build_checks() {
+	local M=9216
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	if [[ ${PV} == *9999* ]]; then
+		M=$(( $(usex miri 128 0) + ${M} ))
+	fi
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex rust_sysroots_bpf 256 0) + ${M} ))
+	M=$(( $(usex rust_sysroots_wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "llvm-core/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	rust_pkg_setup
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix)/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+rust_live_get_sources() {
+	EGIT_REPO_URI="
+		https://anongit.gentoo.org/git/proj/rust-patches.git
+	"
+	EGIT_CHECKOUT_DIR="${WORKDIR}/rust-patches-${RUST_PATCH_VER}"
+	git-r3_src_unpack
+
+	EGIT_REPO_URI="
+		https://github.com/rust-lang/rust.git
+	"
+	EGIT_SUBMODULES=(
+		"*"
+		"-src/gcc"
+	)
+	S="${WORKDIR}/rust"
+	EGIT_CHECKOUT_DIR="${S}"
+	git-r3_src_unpack
+}
+
+src_unpack() {
+	if [[ ${PV} == *9999* ]] ; then
+		rust_live_get_sources
+
+		# Vendor dependencies
+		mkdir "${S}/.cargo" || die # The vendor script has a check for .cargo/config{,.toml}
+		touch "${S}/.cargo/bootstrap.toml" || die
+		local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+		# Configure vendor to use the portage-provided toolchain. This prevents it from
+		# attempting to fetch a `beta` toolchain from the internet.
+		cat <<- _EOF_ > "${T}/vendor-bootstrap.toml"
+			# Suppresses a warning about tracking changes which we don't care about.
+			change-id = "ignore"
+			[build]
+			build = "$(rust_abi "${CBUILD}")"
+			host = ["$(rust_abi "${CHOST}")"]
+			target = ["$(rust_abi "${CHOST}")"]
+			cargo = "${rust_stage0_root}/bin/cargo"
+			rustc = "${rust_stage0_root}/bin/rustc"
+			rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		_EOF_
+		# We're using git sources so we need to run the Vendor script
+		# to ensure that all dependencies are present and up-to-date
+		mkdir "${S}/vendor" || die
+		# This also compiles the 'build helper', there's no way to avoid this.
+		${EPYTHON} "${S}"/x.py vendor -v --config="${T}"/vendor-bootstrap.toml \
+			-j$(get_makeopts_jobs) ||
+				die "Failed to vendor dependencies"
+		# TODO: This has to be generated somehow, this is from a 1.84.x tarball I had lying around.
+		cat <<- _EOF_ > "${S}/.cargo/config.toml"
+			[source.crates-io]
+			replace-with = "vendored-sources"
+
+			[source."git+https://github.com/rust-lang/team"]
+			git = "https://github.com/rust-lang/team"
+			replace-with = "vendored-sources"
+
+			[source.vendored-sources]
+			directory = "vendor"
+		_EOF_
+	elif use verify-sig ; then
+		# Patch tarballs are not signed (but we trust Gentoo infra)
+		verify-sig_verify_detached "${DISTDIR}"/rustc-${RUST_PV}-src.tar.xz{,.asc}
+		default
+	else
+		default
+	fi
+}
+
+src_prepare() {
+	# Commit patches to the appropriate branch in proj/rust-patches.git
+	# then cut a new tag / tarball. Don't add patches to ${FILESDIR}
+	PATCHES=(
+		"${WORKDIR}/rust-patches-${RUST_PATCH_VER}/"
+	)
+
+	if use lto && tc-is-clang && ! tc-ld-is-lld && ! tc-ld-is-mold; then
+		export RUSTFLAGS+=" -C link-arg=-fuse-ld=lld"
+	fi
+
+	default
+}
+
+src_configure() {
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ESYSROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ESYSROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ESYSROOT}/usr/$(get_libdir)"
+	fi
+
+	# Avoid bundled copies of libraries
+	export RUSTONIG_SYSTEM_LIBONIG=1
+	export LIBSQLITE3_SYS_USE_PKG_CONFIG=1
+
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use rust_sysroots_bpf; then
+		rust_targets+=",\"bpfeb-unknown-none\",\"bpfel-unknown-none\""
+	fi
+	if use rust_sysroots_wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	if [[ ${PV} == *9999* ]]; then
+		use miri && tools+=',"miri"'
+	fi
+
+	local rust_stage0_root="$(${RUSTC} --print sysroot || die "Can't determine rust's sysroot")"
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	RUST_EXPERIMENTAL_TARGETS=()
+	for _x in "${!ALL_RUST_EXPERIMENTAL_TARGETS[@]}"; do
+		if [[ ${ALL_RUST_EXPERIMENTAL_TARGETS[${_x}]} == 1 ]] && use ${_x} ; then
+			RUST_EXPERIMENTAL_TARGETS+=( ${_x#llvm_targets_} )
+		fi
+	done
+	RUST_EXPERIMENTAL_TARGETS=${RUST_EXPERIMENTAL_TARGETS[@]}
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	local build_channel
+	local build_miri="false"
+	case "${PV}" in
+		*9999*)
+			build_channel="nightly"
+			;;
+		*beta*)
+			build_channel="beta"
+			;;
+		*)
+			build_channel="stable"
+			;;
+	esac
+
+	# TODO: Add optimized-compiler-builtins for system-llvm to avoid
+	# building bundled compiler-rt.
+	cat <<- _EOF_ > "${S}"/bootstrap.toml
+		# Suppresses a warning about tracking changes which we don't care about.
+		change-id = "ignore"
+		# https://github.com/rust-lang/rust/issues/135358 (bug #947897)
+		profile = "dist"
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = "${RUST_EXPERIMENTAL_TARGETS// /;}"
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		description = "gentoo"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${SLOT}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"${CHOST}-cc\""
+		fi)
+		channel = "${build_channel}"
+		rpath = true
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		omit-git-hash = false
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex rust_sysroots_wasm))
+		$(if use lto && tc-is-clang && ! tc-ld-is-mold; then
+			echo "use-lld = true"
+		fi)
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex rust_sysroots_wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use rust_sysroots_wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		if tc-is-clang; then
+			local wasm_cc=$(tc-getCC)
+			local wasm_cxx=$(tc-getCXX)
+		else
+			local wasm_cc=${CHOST}-clang
+			local wasm_cxx=${CHOST}-clang++
+		fi
+		export CFLAGS_${wasm_target//-/_}="$(
+			CC="${wasm_cc} --target=wasm32-unknown-unknown"
+			filter-flags '-mcpu*' '-march*' '-mtune*'
+			strip-unsupported-flags
+			echo "${CFLAGS}"
+		)"
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.wasm32-unknown-unknown]
+			cc = "${wasm_cc}"
+			cxx = "${wasm_cxx}"
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/bootstrap.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+		if [[ "${cross_rust_target}" == *-uefi ]]; then
+			# Profiler is not supported on bare-metal
+			cat <<- _EOF_ >> "${S}"/bootstrap.toml
+				profiler = false
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" bootstrap.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "bootstrap.toml contents:"
+	cat "${S}"/bootstrap.toml || die
+	echo
+}
+
+src_compile() {
+	# -v will show invocations, -vv "very verbose" is overkill, -vvv "very very verbose" is insane
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -v \
+		--config="${S}"/bootstrap.toml -j$(get_makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen-units
+		crashes
+		codegen-llvm
+		incremental
+		mir-opt
+		pretty
+		run-make
+		run-make-cargo
+	)
+
+	# tests for standard and core library
+	local std_tests=(
+		std
+		core
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly-llvm )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]} ${std_tests[@]}"
+	for i in "tests/${tests[@]}" "library/${std_tests[@]}"; do
+		local t="${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/bootstrap.toml \
+				-j$(get_makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -v \
+		--config="${S}"/bootstrap.toml -j$(get_makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${SLOT}/share/man/
+
+	# bash-completion files are installed by dev-lang/rust-common instead
+	# bug #689562, #689160.
+	rm -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${SLOT}/etc/bash_completion.d" || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	if [[ ${PV} = *9999* ]]; then
+		use miri && symlinks+=( miri cargo-miri )
+	fi
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${RUST_PV%%_*}"
+		if [[ -f "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${SLOT}/bin/${i}" "${ED}/usr/lib/${PN}/${SLOT}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${SLOT}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${SLOT}/lib" "/usr/lib/${PN}/lib-${SLOT}"
+	use rust-analyzer && dosym "${SLOT}/libexec" "/usr/lib/${PN}/libexec-${SLOT}"
+	dosym "${SLOT}/share/man" "/usr/lib/${PN}/man-${SLOT}"
+	dosym "rust/${SLOT}/lib/rustlib" "/usr/lib/rustlib-${SLOT}"
+	dosym "../../lib/${PN}/${SLOT}/share/doc/rust" "/usr/share/doc/${RUST_P}"
+
+	newenvd - "50${RUST_P}" <<-_EOF_
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${SLOT}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${SLOT}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${PN}-${SLOT}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${RUST_P}"
+	fi
+	if [[ ${SLOT} == *9999* ]] && use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${RUST_P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${RUST_P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/lib/rust/libexec >> "${T}/provider-${RUST_P}"
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${RUST_P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${PN}-${SLOT}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -v --config="${S}"/bootstrap.toml \
+			-j$(get_makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${SLOT}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version llvm-core/lldb; then
+		elog "Rust installs helper scripts for calling GDB and LLDB,"
+		elog "for convenience they are installed under /usr/bin/rust-{gdb,lldb}-${RUST_PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}