Problem evaluating `gcc` with `langRust = true`

Development Nixpkgs Architecture
1

Hey, I’m working on packaging gccrs and gcobol for nixos, like how gccgo is already packaged. You can see my work in gccrs, gcobol: improve support and package by sempiternal-aurora · Pull Request #507407 · NixOS/nixpkgs · GitHub . However, I’m running into evaluation issues with gccrs. When I override gcc.cc with withRust = true, I get an evaluation error, but overriding gcc15 has no similar problems, even though they are the same package? Can someone help me look at this, I’m extremely confused.

The problem seems to inherantly come from the optionals langRust [ cargo ] in pkgs/development/compilers/gcc/common/dependencies.nix, added in gcc: provide build support for gccrs by nagy · Pull Request #332738 · NixOS/nixpkgs · GitHub . Removing this fixes the evaluation, but breaks the gccrs build as it needs cargo for some rust in the code. Is there some problem with how the dependencies are specified, is there a circular import problem where we’re overriding the gcc that is used to build the rust system somehow? The full trace just doesn’t give me a lot to go on from what I can see. Any help is highly appreciated.

error:
       … while calling the 'derivationStrict' builtin
         at <nix/derivation-internal.nix>:37:12:
           36|
           37|   strict = derivationStrict drvAttrs;
             |            ^
           38|

       … while evaluating derivation 'gccrs-wrapper-15.2.0'
         whose name attribute is located at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/stdenv/generic/make-derivation.nix:536:13

       … while evaluating attribute 'cc' of derivation 'gccrs-wrapper-15.2.0'

       … while calling the 'getAttr' builtin
         at <nix/derivation-internal.nix>:50:17:
           49|     value = commonAttrs // {
           50|       outPath = builtins.getAttr outputName strict;
             |                 ^
           51|       drvPath = strict.drvPath;

       … while calling the 'derivationStrict' builtin
         at <nix/derivation-internal.nix>:37:12:
           36|
           37|   strict = derivationStrict drvAttrs;
             |            ^
           38|

       … while evaluating derivation 'gccrs-15.2.0'
         whose name attribute is located at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/stdenv/generic/make-derivation.nix:536:13

       … while evaluating attribute 'nativeBuildInputs' of derivation 'gccrs-15.2.0'
         at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/stdenv/generic/make-derivation.nix:585:13:
          584|             depsBuildBuild = elemAt (elemAt dependencies 0) 0;
          585|             nativeBuildInputs = elemAt (elemAt dependencies 0) 1;
             |             ^
          586|             depsBuildTarget = elemAt (elemAt dependencies 0) 2;

       … while calling the 'getAttr' builtin
         at <nix/derivation-internal.nix>:50:17:
           49|     value = commonAttrs // {
           50|       outPath = builtins.getAttr outputName strict;
             |                 ^
           51|       drvPath = strict.drvPath;

       … while calling the 'derivationStrict' builtin
         at <nix/derivation-internal.nix>:37:12:
           36|
           37|   strict = derivationStrict drvAttrs;
             |            ^
           38|

       … while evaluating derivation 'cargo-1.94.0'
         whose name attribute is located at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/stdenv/generic/make-derivation.nix:536:13

       … while evaluating attribute 'buildInputs' of derivation 'cargo-1.94.0'
         at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/stdenv/generic/make-derivation.nix:588:13:
          587|             depsHostHost = elemAt (elemAt dependencies 1) 0;
          588|             buildInputs = elemAt (elemAt dependencies 1) 1;
             |             ^
          589|             depsTargetTarget = elemAt (elemAt dependencies 2) 0;

       … while calling the 'getAttr' builtin
         at <nix/derivation-internal.nix>:50:17:
           49|     value = commonAttrs // {
           50|       outPath = builtins.getAttr outputName strict;
             |                 ^
           51|       drvPath = strict.drvPath;

       … while calling the 'derivationStrict' builtin
         at <nix/derivation-internal.nix>:37:12:
           36|
           37|   strict = derivationStrict drvAttrs;
             |            ^
           38|

       … while evaluating derivation 'curl-8.18.0'
         whose name attribute is located at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/stdenv/generic/make-derivation.nix:536:13

       … while evaluating attribute 'configureFlags' of derivation 'curl-8.18.0'
         at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/stdenv/generic/make-derivation.nix:599:13:
          598|             # This parameter is sometimes a string, sometimes null, and sometimes a list, yuck
          599|             configureFlags =
             |             ^
          600|               configureFlags

       … from call site
         at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/by-name/cu/curlMinimal/package.nix:190:6:
          189|     (lib.withFeature pslSupport "libpsl")
          190|     (lib.withFeatureAs brotliSupport "brotli" (lib.getDev brotli))
             |      ^
          191|     (lib.withFeatureAs gnutlsSupport "gnutls" (lib.getDev gnutls))

       … while calling 'withFeatureAs'
         at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/lib/strings.nix:2485:20:
         2484|   withFeatureAs =
         2485|     flag: feature: value:
             |                    ^
         2486|     withFeature flag feature + optionalString flag "=${value}";

       … from call site
         at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/lib/strings.nix:2486:32:
         2485|     flag: feature: value:
         2486|     withFeature flag feature + optionalString flag "=${value}";
             |                                ^
         2487|

       … while calling 'optionalString'
         at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/lib/strings.nix:767:26:
          766|   */
          767|   optionalString = cond: string: if cond then string else "";
             |                          ^
          768|

       … while calling the 'getAttr' builtin
         at <nix/derivation-internal.nix>:50:17:
           49|     value = commonAttrs // {
           50|       outPath = builtins.getAttr outputName strict;
             |                 ^
           51|       drvPath = strict.drvPath;

       … while calling the 'derivationStrict' builtin
         at <nix/derivation-internal.nix>:37:12:
           36|
           37|   strict = derivationStrict drvAttrs;
             |            ^
           38|

       … while evaluating derivation 'brotli-1.2.0'
         whose name attribute is located at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/stdenv/generic/make-derivation.nix:536:13

       … while evaluating attribute 'nativeBuildInputs' of derivation 'brotli-1.2.0'
         at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/stdenv/generic/make-derivation.nix:585:13:
          584|             depsBuildBuild = elemAt (elemAt dependencies 0) 0;
          585|             nativeBuildInputs = elemAt (elemAt dependencies 0) 1;
             |             ^
          586|             depsBuildTarget = elemAt (elemAt dependencies 0) 2;

       … while calling the 'getAttr' builtin
         at <nix/derivation-internal.nix>:50:17:
           49|     value = commonAttrs // {
           50|       outPath = builtins.getAttr outputName strict;
             |                 ^
           51|       drvPath = strict.drvPath;

       … while calling the 'derivationStrict' builtin
         at <nix/derivation-internal.nix>:37:12:
           36|
           37|   strict = derivationStrict drvAttrs;
             |            ^
           38|

       … while evaluating derivation 'cmake-4.1.2'
         whose name attribute is located at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/stdenv/generic/make-derivation.nix:536:13

       … while evaluating attribute 'buildInputs' of derivation 'cmake-4.1.2'
         at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/stdenv/generic/make-derivation.nix:588:13:
          587|             depsHostHost = elemAt (elemAt dependencies 1) 0;
          588|             buildInputs = elemAt (elemAt dependencies 1) 1;
             |             ^
          589|             depsTargetTarget = elemAt (elemAt dependencies 2) 0;

       … while calling the 'getAttr' builtin
         at <nix/derivation-internal.nix>:50:17:
           49|     value = commonAttrs // {
           50|       outPath = builtins.getAttr outputName strict;
             |                 ^
           51|       drvPath = strict.drvPath;

       … while calling the 'derivationStrict' builtin
         at <nix/derivation-internal.nix>:37:12:
           36|
           37|   strict = derivationStrict drvAttrs;
             |            ^
           38|

       … while evaluating derivation 'curl-8.18.0'
         whose name attribute is located at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/stdenv/generic/make-derivation.nix:536:13

       … while evaluating attribute 'propagatedBuildInputs' of derivation 'curl-8.18.0'
         at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/stdenv/generic/make-derivation.nix:595:13:
          594|             depsHostHostPropagated = elemAt (elemAt propagatedDependencies 1) 0;
          595|             propagatedBuildInputs = elemAt (elemAt propagatedDependencies 1) 1;
             |             ^
          596|             depsTargetTargetPropagated = elemAt (elemAt propagatedDependencies 2) 0;

       … while calling the 'getAttr' builtin
         at <nix/derivation-internal.nix>:50:17:
           49|     value = commonAttrs // {
           50|       outPath = builtins.getAttr outputName strict;
             |                 ^
           51|       drvPath = strict.drvPath;

       … while calling the 'derivationStrict' builtin
         at <nix/derivation-internal.nix>:37:12:
           36|
           37|   strict = derivationStrict drvAttrs;
             |            ^
           38|

       … while evaluating derivation 'nghttp2-1.67.1'
         whose name attribute is located at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/stdenv/generic/make-derivation.nix:536:13

       … while evaluating attribute 'buildInputs' of derivation 'nghttp2-1.67.1'
         at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/stdenv/generic/make-derivation.nix:588:13:
          587|             depsHostHost = elemAt (elemAt dependencies 1) 0;
          588|             buildInputs = elemAt (elemAt dependencies 1) 1;
             |             ^
          589|             depsTargetTarget = elemAt (elemAt dependencies 2) 0;

       … while calling the 'getAttr' builtin
         at <nix/derivation-internal.nix>:50:17:
           49|     value = commonAttrs // {
           50|       outPath = builtins.getAttr outputName strict;
             |                 ^
           51|       drvPath = strict.drvPath;

       … while calling the 'derivationStrict' builtin
         at <nix/derivation-internal.nix>:37:12:
           36|
           37|   strict = derivationStrict drvAttrs;
             |            ^
           38|

       … while evaluating derivation 'libev-4.33'
         whose name attribute is located at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/stdenv/generic/make-derivation.nix:536:13

       … while evaluating attribute 'patches' of derivation 'libev-4.33'
         at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/stdenv/generic/make-derivation.nix:610:21:
          609|
          610|             inherit patches;
             |                     ^
          611|

       … while calling a functor (an attribute set with a '__functor' attribute)
         at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/by-name/li/libev/package.nix:26:6:
           25|   patches = [
           26|     (fetchpatch {
             |      ^
           27|       url = "https://raw.githubusercontent.com/freebsd/freebsd-ports/21a6f0f5829384117dfc1ed11ad67954562ef7d6/devel/libev/files/patch-ev.c";

       … from call site
         at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/lib/trivial.nix:1081:5:
         1080|     # TODO: Should we add call-time "type" checking like built in?
         1081|     __functor = self: f;
             |     ^
         1082|     __functionArgs = args;

       … while calling anonymous lambda
         at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/build-support/fetchpatch/default.nix:13:1:
           12|
           13| {
             | ^
           14|   relative ? null,

       … from call site
         at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/build-support/fetchpatch/default.nix:41:1:
           40| in
           41| lib.throwIfNot (excludes == [ ] || includes == [ ])
             | ^
           42|   "fetchpatch: cannot use excludes and includes simultaneously"

       error: function 'anonymous lambda' called with unexpected argument 'nativeBuildInputs'
       at /nix/store/dkz5lh7c0m6rpj93cd3nc8j65zvar1m1-source/pkgs/build-support/fetchurl/boot.nix:10:1:
            9|
           10| {
             | ^
           11|   url ? builtins.head urls,
1 Like
2

The problem you’re running into is that gcc.cc != gcc15.cc, at least not exactly. gcc points to previous bootstrapping stage of gcc (it is the same as stdenv.cc which is used to build every regular package in Nixpkgs, more or less, including gcc15). (I’m currently unable to explain why this is exactly because it’s not quite apparent from the gcc definition site, will have to think about it.) This bootstrapping stage still uses the more limited builtin fetchurl implementation of Nix which doesn’t support certain features, hence the error message.

The error then occurs because gcc.cc.override { } recomputes the gcc derivation with the same inputs/scope (which is the previous bootstrapping stage), so only the limited fetchurl implementation remains available. cargo seems to depend on a fully featured version of curl which in turn depends on libev which uses fetchpatch (since https://github.com/NixOS/nixpkgs/pull/468563, I’m not sure whether it actually should). This then breaks with the bootstrap fetchurl implementation.

You may have better luck with overriding pkgs."gcc${toString default-gcc-version}".

3 Likes
3

Thanks for the explanation. The only thing I’m confused about is why gcc is the stdenv gcc in the first place, isn’t it set just a few lines above in all-packages.nix to be pkgs.”gcc${toString default-gcc-version}”?

4

and the stdenv definition uses that definition (with additional override machinery)

5

Right, the linux stdenv bootstrapper uses gcc as the main attribute that is redefined in the different stages, hence we are left with the deps from the previous stage in the end.