pkgsCross.gnu64.stdenv fails to build on x86_64-linux

[uri-canva]

error: builder for '/nix/store/h1mi656mpg23rj5d7kv4z3alwzgrf3wj-x86_64-unknown-linux-gnu-stage-static-gcc-12.3.0.drv' failed with exit code 1;
       last 10 log lines:
       > /nix/store/c2bq8xsayc90s33fd5xbm1vh5lrmwcfq-coreutils-9.3/bin/install -c -m 644 unwind.h /nix/store/i4zdpqis141x9i5y6iylpq3ddvy79ng8-x86_64-unknown-linux-gnu-stage-static-gcc-12.3.0/lib/gcc/x86_64-unknown-linux-gnu/12.3.0/include
       > /nix/store/51sszqz1d9kpx480scb1vllc00kxlx79-bash-5.2-p15/bin/bash ../../../gcc-12.3.0/libgcc/../mkinstalldirs /nix/store/i4zdpqis141x9i5y6iylpq3ddvy79ng8-x86_64-unknown-linux-gnu-stage-static-gcc-12.3.0/lib/gcc/x86_64-unknown-linux-gnu/12.3.0/include
       > /nix/store/c2bq8xsayc90s33fd5xbm1vh5lrmwcfq-coreutils-9.3/bin/install -c -m 644 ../../../gcc-12.3.0/libgcc/gcov.h /nix/store/i4zdpqis141x9i5y6iylpq3ddvy79ng8-x86_64-unknown-linux-gnu-stage-static-gcc-12.3.0/lib/gcc/x86_64-unknown-linux-gnu/12.3.0/include
       > make[1]: Leaving directory '/build/build/x86_64-unknown-linux-gnu/libgcc'
       > Moving /nix/store/i4zdpqis141x9i5y6iylpq3ddvy79ng8-x86_64-unknown-linux-gnu-stage-static-gcc-12.3.0/x86_64-unknown-linux-gnu/lib/libgcc_s.so to /nix/store/1sc78iyqi0bx2a2dbba2h6jycj58p2hh-x86_64-unknown-linux-gnu-stage-static-gcc-12.3.0-lib/x86_64-unknown-linux-gnu/lib/libgcc_s.so
       > Moving /nix/store/i4zdpqis141x9i5y6iylpq3ddvy79ng8-x86_64-unknown-linux-gnu-stage-static-gcc-12.3.0/x86_64-unknown-linux-gnu/lib/libgcc_s.so.1 to /nix/store/1sc78iyqi0bx2a2dbba2h6jycj58p2hh-x86_64-unknown-linux-gnu-stage-static-gcc-12.3.0-lib/x86_64-unknown-linux-gnu/lib/libgcc_s.so.1
       > Removing empty /nix/store/i4zdpqis141x9i5y6iylpq3ddvy79ng8-x86_64-unknown-linux-gnu-stage-static-gcc-12.3.0/x86_64-unknown-linux-gnu/lib/ and (possibly) its parents
       > /nix/store/qr60k7sz61hvv2baadlfv5qjr8q7vlg6-builder.sh: line 243: type: install_name_tool: not found
       > preFixupLibGccPhase
       > mv: cannot stat '/nix/store/1sc78iyqi0bx2a2dbba2h6jycj58p2hh-x86_64-unknown-linux-gnu-stage-static-gcc-12.3.0-lib/lib/libgcc_s.so': No such file or directory
       For full logs, run 'nix-store -l /nix/store/h1mi656mpg23rj5d7kv4z3alwzgrf3wj-x86_64-unknown-linux-gnu-stage-static-gcc-12.3.0.drv'.
error: 1 dependencies of derivation '/nix/store/927jr7zwi4ll0y8d4g1dfx6s7syq5a7h-glibc-x86_64-unknown-linux-gnu-2.37-8.drv' failed to build
error: 1 dependencies of derivation '/nix/store/2rfx2h31jbsld7p8v3r2c8q7ha39vmqw-x86_64-unknown-linux-gnu-stage-final-gcc-wrapper-12.3.0.drv' failed to build
error: 1 dependencies of derivation '/nix/store/7rm333lrks2j5r2hy4dy3g0bxghmn4jz-stdenv-linux.drv' failed to build

Broken by #238154.

[ghost]

⚠️ Note: this wasn't working even before #238154. ⚠️

Nixpkgs gcc expression has a lot of problems, and has always had a lot of problems, when hostPlatform.config == buildPlatform.config but hostPlatform != buildPlatform.

gcc is designed to make install differently when the two config values are equal, because it's designed for an FHS universe where there is only one /usr. So it has to be careful not to overwrite the hostPlatform libraries when it installs the buildPlatform libraries.

Nixpkgs doesn't have this problem, and we generally want stuff in $lib, not $lib/${targetConfig}/lib. But it's a game of whack-a-mole with gcc's Makefiles because "what upstream wants" is and always will be "what most distros do" -- which isn't what we do.

Please be patient.

Right now, touching anything in builder.sh causes a full stdenv rebuild, meaning a weeks-long PR cycle through staging. This friction is why our gcc expression is in such a sorry state of disrepair. Nobody wants to work on it when it's so fragile and cumbersome.

#237856 will take us a long way towards making it easier to fix these kinds of bugs, without a stdenv rebuild, and without having to go through staging. Please be patient and wait a bit, so I can fix this problem the easy way once that's done, instead of having to fix it the really really hard and painful way right this instant.

If you're in urgent need of a fix, try disabling link-time optimization (enableLTO=false).

[uri-canva]

Exciting! Will that link up with some of the work being done for #87909? Looking forward to it!

[ghost]

Exciting! Will that link up with some of the work being done for #87909?

I am very much in favor of that PR. If we can get consensus around it being a good idea (which I think it is) then I will certainly implement it.

Also: once I fix this I will add pkgsCross.gnu64.stdenv to pkgs.tests.cross.sanity so this doesn't happen again:

• we need a pkgsCross smoke test #243320

[dongcarl]

Has there been more progress on this? Does this work on -unstable now?

[ghost]

Fixed by

• gcc.libgcc: compare host and target platforms, rather than their triples #264976