Help with cross-compilation aarch64-darwin --> aarch64-unknown-linux-musl

[DavSanchez]

Hello!

Following conversations from an issue and its recent PR, I have attempted to cross-compile an existing project from a macOS machine targeting aarch64-unknown-linux-musl. This is my definition, almost a C&P of the example for cross-compiling provided in the docs but using fenix to provide the toolchain and for musl as target instead (this is also using flake-parts to select system and expose the inputs, but I don't think this is having an impact for now):

{ inputs, ... }:
{
  perSystem =
    { system, ... }:
    let
      target = "aarch64-unknown-linux-musl";
      pkgs = import inputs.nixpkgs {
        crossSystem = {
          config = target;
        };
        localSystem = system;
      };
      inherit (pkgs) lib;

      # Bring the functionality of `crane` into the current scope, with a selected Rust toolchain.
      craneLib = (inputs.crane.mkLib pkgs).overrideToolchain (
        _:
        with inputs.fenix.packages.${system};
        combine [
          stable.toolchain
          targets.${target}.stable.rust-std
        ]
      );

      crateExpression =
        {
          libiconv,
          lib,
          stdenv,
        }:
        craneLib.buildPackage
          ({
            src = ../.;
            strictDeps = true;
            CARGO_BUILD_RUSTFLAGS = "-C target-feature=+crt-static";
            nativeBuildInputs =
              [ ]
              ++ lib.optionals stdenv.buildPlatform.isDarwin [
                libiconv
              ];
          }
          // craneLib.crateNameFromCargoToml { cargoToml = ../workspace-member/Cargo.toml; });

      my-crate = pkgs.callPackage crateExpression { };
    in
    {
      checks = { inherit my-crate; };
      packages.my-crate = my-crate;
    };
}

I was under the impression that the relevant environment variables and linker references would be resolved automatically with what #794 had added, and in fact it kind of shows the variables being set up in the .drv:

$ bat /nix/store/wb0bwmv5b65i17ijcy51hnnifnrsipwn-<REDACTED>-aarch64-unknown-linux-musl-0.36.1.drv
Derive([("out","/nix/store/7ga8np7sn9h8sfgqd2w66f0dbgih3zcz-<REDACTED>-aarch64-unknown-linux-musl-0.36.1","","")],[("/nix/store/0h5npx2qpx294071rw7i1kmy84dww750-installFromCargoBuildLogHook.drv",["out"]),("/nix/store/15ivc1hkmh8sk6lw9wxbpspypw1xcc8n-inheritCargoArtifactsHook.drv",["out"]),("/nix/store/19kfqz8ms2m90nxvlx3yalv3ci5wjgbg-rsync-3.4.1.drv",["out"]),("/nix/store/d0armws6j3kfp9sazl0n9dbxihcmzx2c-aarch64-unknown-linux-musl-gcc-wrapper-13.3.0.drv",["out"]),("/nix/store/f5alh6zdm70kczpj17wvx81kb4pcmr04-installCargoArtifactsHook.drv",["out"]),("/nix/store/jcmq21whggqlwvqvapj5f70wvswf5h65-configureCargoVendoredDepsHook.drv",["out"]),("/nix/store/jkpdhpd03wf4cgi2ikakfxy60mm128fl-replaceCargoLockHook.drv",["out"]),("/nix/store/kfzmpgrn7ak82w72nrmi3n0swxgwdbms-configureCargoCommonVarsHook.drv",["out"]),("/nix/store/kr0383fm1xw1c4cwnnwy9pszq88c65y5-libiconv-109.drv",["dev"]),("/nix/store/mnxw4zjs9pbisybnf6a1vr1c9cqc6daq-cargoHelperFunctionsHook.drv",["out"]),("/nix/store/njyyp3qjdka3l8rsc1sn99pnlf6z1d4m-zstd-1.5.6.drv",["dev"]),("/nix/store/pjz23hwbaqalnxv2hnx7cja7wk7wfzvq-removeReferencesToVendoredSourcesHook.drv",["out"]),("/nix/store/pmvabpmdk82agba64fl2fp93pc1xydmr-<REDACTED>-deps-aarch64-unknown-linux-musl-0.36.1.drv",["out"]),("/nix/store/qr7c2z3iwllns6nz5cflv33zs8nv948x-rust-mixed.drv",["out"]),("/nix/store/rfd5p10r2lvjcznjck6k078mnv9pqpm3-bash-5.2p37.drv",["out"]),("/nix/store/rhmhxhwjwmykhk8fhv62p53c9slawwxs-clang-wrapper-16.0.6.drv",["out"]),("/nix/store/xvyqhfpblv3qddmvm1xiah0mh9xf069f-removeReferencesToRustToolchainHook.drv",["out"]),("/nix/store/y0ns8vlj8g888gawbi2x5rmcmw0rrq37-vendor-cargo-deps.drv",["out"]),("/nix/store/zffbgxarwi5iyf1rmi288zg8gh50m8g6-stdenv-darwin.drv",["out"])],["/nix/store/i3wg8ia7pwqnm09bh3ky6xdcipbvzdk3-source","/nix/store/qa848i01y1iw4i4hhdsa4v4qw00br594-cross-file.conf","/nix/store/v6x3cs394jgqfbi0a42pam708flxaphh-default-builder.sh"],"aarch64-darwin","/nix/store/qzwsj5ihx6kjwikr0g77dnhcfxm1by68-bash-5.2p37/bin/bash",["-e","/nix/store/v6x3cs394jgqfbi0a42pam708flxaphh-default-builder.sh"],[("CARGO_BUILD_RUSTFLAGS","-C target-feature=+crt-static"),("NIX_HARDENING_ENABLE","bindnow format fortify fortify3 pic relro stackprotector strictoverflow zerocallusedregs pie"),("__CRANE_EXPORT_AR_AARCH64_APPLE_DARWIN","ar"),("__CRANE_EXPORT_AR_AARCH64_UNKNOWN_LINUX_MUSL","aarch64-unknown-linux-musl-ar"),("__CRANE_EXPORT_CARGO_BUILD_TARGET","aarch64-unknown-linux-musl"),("__CRANE_EXPORT_CARGO_TARGET_AARCH64_APPLE_DARWIN_LINKER","cc"),("__CRANE_EXPORT_CARGO_TARGET_AARCH64_UNKNOWN_LINUX_MUSL_LINKER","aarch64-unknown-linux-musl-cc"),("__CRANE_EXPORT_CC_AARCH64_APPLE_DARWIN","cc"),("__CRANE_EXPORT_CC_AARCH64_UNKNOWN_LINUX_MUSL","aarch64-unknown-linux-musl-cc"),("__CRANE_EXPORT_CXX_AARCH64_APPLE_DARWIN","c++"),("__CRANE_EXPORT_CXX_AARCH64_UNKNOWN_LINUX_MUSL","aarch64-unknown-linux-musl-c++"),("__CRANE_EXPORT_HOST_AR","ar"),("__CRANE_EXPORT_HOST_CC","cc"),("__CRANE_EXPORT_HOST_CXX","c++"),("__CRANE_EXPORT_TARGET_AR","aarch64-unknown-linux-musl-ar"),("__CRANE_EXPORT_TARGET_CC","aarch64-unknown-linux-musl-cc"),("__CRANE_EXPORT_TARGET_CXX","aarch64-unknown-linux-musl-c++"),("__darwinAllowLocalNetworking",""),("__impureHostDeps","/bin/sh /usr/lib/libSystem.B.dylib /usr/lib/system/libunc.dylib /dev/zero /dev/random /dev/urandom /bin/sh"),("__propagatedImpureHostDeps",""),("__propagatedSandboxProfile",""),("__sandboxProfile",""),("__structuredAttrs",""),("buildInputs",""),("buildPhase","runHook preBuild\ncargo --version\ncargoBuildLog=$(mktemp cargoBuildLogXXXX.json)\ncargoWithProfile build --message-format json-render-diagnostics --locked >\"$cargoBuildLog\"\n\nrunHook postBuild\n"),("builder","/nix/store/qzwsj5ihx6kjwikr0g77dnhcfxm1by68-bash-5.2p37/bin/bash"),("cargoArtifacts","/nix/store/8ihmk89v2l5fgchkwygi2zzv8y4kax55-<REDACTED>-deps-aarch64-unknown-linux-musl-0.36.1"),("cargoVendorDir","/nix/store/v7rih35k5axzdfpkpss05zhd44yd7zy3-vendor-cargo-deps"),("checkPhase","runHook preCheck\ncargoWithProfile test --locked \n\nrunHook postCheck\n"),("cmakeFlags","-DCMAKE_SYSTEM_NAME=Linux -DCMAKE_SYSTEM_PROCESSOR=aarch64 -DCMAKE_HOST_SYSTEM_NAME=Darwin -DCMAKE_HOST_SYSTEM_PROCESSOR=aarch64"),("configureFlags","--build=aarch64-apple-darwin --host=aarch64-unknown-linux-musl"),("configurePhase","runHook preConfigure\necho default configurePhase, nothing to do\nrunHook postConfigure\n"),("depsBuildBuild",""),("depsBuildBuildPropagated",""),("depsBuildTarget",""),("depsBuildTargetPropagated",""),("depsHostHost",""),("depsHostHostPropagated",""),("depsTargetTarget",""),("depsTargetTargetPropagated",""),("doCheck",""),("doInstallCargoArtifacts",""),("doInstallCheck",""),("installPhase","runHook preInstall\nif [ -n \"$postBuildInstallFromCargoBuildLogOut\" -a -d \"$postBuildInstallFromCargoBuildLogOut\" ]; then\n  echo \"actually installing contents of $postBuildInstallFromCargoBuildLogOut to $out\"\n  mkdir -p $out\n  find \"$postBuildInstallFromCargoBuildLogOut\" -mindepth 1 -maxdepth 1 | xargs -r mv -t $out\nelse\n  echo '!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\n$postBuildInstallFromCargoBuildLogOut is either undefined or does not point to a\nvalid location! By default `buildPackage` will expect that cargo'\\''s output was\ncaptured and the resulting binaries preinstalled in a temporary location to avoid\ninterference by the check phase.\n\nIf you are defining your own custom build step, you have two options:\n1. override `installPhaseCommand` with the appropriate installation steps\n2. ensure that cargo'\\''s build log is captured in a file and point\n   $postBuildInstallFromCargoBuildLogOut at it\n\nAt a minimum, the latter option can be achieved with a build phase that runs:\n     cargoBuildLog=$(mktemp cargoBuildLogXXXX.json)\n     cargo build --release --message-format json-render-diagnostics >\"$cargoBuildLog\"\n     postBuildInstallFromCargoBuildLogOut=$(mktemp -d cargoBuildTempOutXXXX)\n     installFromCargoBuildLog \"$postBuildInstallFromCargoBuildLogOut\" \"$cargoBuildLog\"\n!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\n'\n\n  false\nfi\n\nrunHook postInstall\n"),("mesonFlags","--cross-file=/nix/store/qa848i01y1iw4i4hhdsa4v4qw00br594-cross-file.conf"),("name","<REDACTED>-aarch64-unknown-linux-musl-0.36.1"),("nativeBuildInputs","/nix/store/yxac2lhw00d1gi6c7kl6dlwnrmddhp23-libiconv-109-dev /nix/store/vpnz8l9qk2q04r72ji6lflg68na95fab-installFromCargoBuildLogHook /nix/store/26qfz98bmiifdybxcjamkmgwbdfnl4f9-removeReferencesToRustToolchainHook /nix/store/m83ky4dy8crdwl8cs3cm0q9h4p917l8f-removeReferencesToVendoredSourcesHook /nix/store/9fbzrya8pqaw0lfhg9q0g3pscy2aw7kz-clang-wrapper-16.0.6 /nix/store/2vj1s2r39dl0rb87lp41sl48pmj98170-aarch64-unknown-linux-musl-gcc-wrapper-13.3.0 /nix/store/zjl03z3r8h3zycp55m41kvlqz28k5had-rust-mixed /nix/store/gh6j5fcjngf9310p41aap7918ngqdy5b-cargoHelperFunctionsHook /nix/store/kf7jf539a0lnn0y6p4w63pfm725pqyfn-configureCargoCommonVarsHook /nix/store/dhhvckqp9y4d6glbbh1fcin03c6q1y75-configureCargoVendoredDepsHook /nix/store/arii4abzhkh6d0g3jaj8y6hww1kz2nx9-inheritCargoArtifactsHook /nix/store/yc1qbivka3h54p288mgwwqbpkrqs802w-installCargoArtifactsHook /nix/store/xx7h7dfvnb5w7hc5wihd69xfs7bq61hc-replaceCargoLockHook /nix/store/7frifb58kqclnd2a5gjarimkcily05q9-rsync-3.4.1 /nix/store/zjl03z3r8h3zycp55m41kvlqz28k5had-rust-mixed /nix/store/m53a8mrkhjdrvsy8jgcs5s7n3gk5x179-zstd-1.5.6-dev"),("out","/nix/store/7ga8np7sn9h8sfgqd2w66f0dbgih3zcz-<REDACTED>-aarch64-unknown-linux-musl-0.36.1"),("outputs","out"),("patches",""),("pname","<REDACTED>"),("propagatedBuildInputs",""),("propagatedNativeBuildInputs",""),("src","/nix/store/i3wg8ia7pwqnm09bh3ky6xdcipbvzdk3-source"),("stdenv","/nix/store/jaqbj4kyf88gp2h5k6984k594nfv4gz4-stdenv-darwin"),("strictDeps","1"),("system","aarch64-darwin"),("version","0.36.1")])

However, when attempting to build I get the error of libiconv not being found:

$ nix build .#package
error: builder for '/nix/store/pmvabpmdk82agba64fl2fp93pc1xydmr-<REDACTED>-deps-aarch64-unknown-linux-musl-0.36.1.drv' failed with exit code 101;
       last 25 log lines:
       >     Checking deranged v0.4.0
       >     Checking concurrent-queue v2.5.0
       >     Checking event-listener v5.4.0
       >    Compiling aws-lc-rs v1.13.0
       > error: linking with `cc` failed: exit status: 1
       >   |
       >   = note: env -u IPHONEOS_DEPLOYMENT_TARGET -u TVOS_DEPLOYMENT_TARGET -u XROS_DEPLOYMENT_TARGET LC_ALL="C" PATH="/nix/store/zjl03z3r8h3zycp55m41kvlqz28k5had-rust-mixed/lib/rustlib/aarch64-apple-darwin/bin:/nix/store/csjwwprnp033h6gbqrarifa0f76m61rd-libiconv-109/bin:/nix/store/9fbzrya8pqaw0lfhg9q0g3pscy2aw7kz-clang-wrapper-16.0.6/bin:/nix/store/a3cb7da0k1k4px3r6i0ar3nxr605g5yv-clang-16.0.6/bin:/nix/store/628n22773lxvj5w8pmn0wq9zag7nzd7w-coreutils-9.5/bin:/nix/store/kvx50ndpfcx73w39inrk63fnfi47wqwy-cctools-binutils-darwin-wrapper-1010.6/bin:/nix/store/5lyy560i21kd9flai0g81kwdkh82pr0m-cctools-binutils-darwin-1010.6/bin:/nix/store/2vj1s2r39dl0rb87lp41sl48pmj98170-aarch64-unknown-linux-musl-gcc-wrapper-13.3.0/bin:/nix/store/dwdqz6zcy38mbycl878dg7bkkjigcnfh-aarch64-unknown-linux-musl-gcc-13.3.0/bin:/nix/store/igdkqqq5zzhbqqbcz5jxv1fi3fw0mqah-musl-aarch64-unknown-linux-musl-1.2.5-bin/bin:/nix/store/13jcszfcc8xl1dz6phl36f3vmb7zpyid-coreutils-9.5/bin:/nix/store/6nkq4fljfki89v0mm8wf441w8y2w6say-aarch64-unknown-linux-musl-binutils-wrapper-2.43.1/bin:/nix/store/ivwqfvlzg2iry0lf1ga3bp8wc0nlwrfl-aarch64-unknown-linux-musl-binutils-2.43.1/bin:/nix/store/zjl03z3r8h3zycp55m41kvlqz28k5had-rust-mixed/bin:/nix/store/7frifb58kqclnd2a5gjarimkcily05q9-rsync-3.4.1/bin:/nix/store/w4qfr9w2pxbpz7ksy1y3rl43wiagvcpv-zstd-1.5.6-bin/bin:/nix/store/5g4pw9bc43xbhrdcjv6j4sdi1l9yldrr-zstd-1.5.6/bin:/nix/store/v8zqq0qg2hky6dzawb26ym1rdv5gs512-patchelf-0.15.0/bin:/nix/store/628n22773lxvj5w8pmn0wq9zag7nzd7w-coreutils-9.5/bin:/nix/store/70jvidma235cyw4gg80bz9vlc0d6184d-findutils-4.10.0/bin:/nix/store/gcsymgijgn2lh5d3n9k90gjjps7lcwmj-diffutils-3.10/bin:/nix/store/aqqchdzlk623ic39hcnd8irwgcpl8s2f-gnused-4.9/bin:/nix/store/vk5kab83vjh7ihvygdfbv72w838klc1d-gnugrep-3.11/bin:/nix/store/fsx7qv5fkc4r6bigcpddg88qhh24sp1i-gawk-5.3.1/bin:/nix/store/yy7y4mk7jy6imwfk8fjy9nhh53ihz7s3-gnutar-1.35/bin:/nix/store/4d1h0gzca9992cmx2ivmmjqfwl2432px-gzip-1.13/bin:/nix/store/b23vn7ragh7jwz5i3z3vhn6m00rrkiax-bzip2-1.0.8-bin/bin:/nix/store/60h3w4y3av3ss1bw6hbqivk59f9ydqxl-gnumake-4.4.1/bin:/nix/store/qzwsj5ihx6kjwikr0g77dnhcfxm1by68-bash-5.2p37/bin:/nix/store/g4s3mv5d6sk845kqspcrkp7xkaa9s5j2-patch-2.7.6/bin:/nix/store/x82gz86ymhj9mivikyf77ny9j1ajic7p-xz-5.6.3-bin/bin:/nix/store/pp6kblicnsalm9q3adbm0a51kvsxv9n0-file-5.45/bin" VSLANG="1033" ZERO_AR_DATE="1" "cc" "/private/tmp/nix-build-<REDACTED>-deps-aarch64-unknown-linux-musl-0.36.1.drv-0/rustcDOHGQQ/symbols.o" "<5 object files omitted>" "/private/tmp/nix-build-<REDACTED>-deps-aarch64-unknown-linux-musl-0.36.1.drv-0/source/target/release/deps/{libcc-2055fdd5e3d64d09.rlib,libjobserver-5a5fc4f341d03f3a.rlib,liblibc-b1fda287d7a91569.rlib,libshlex-16a10314ad0b1e79.rlib}" "/nix/store/ird7hdw2zm65s2vmj6sjkd546vzv78ax-rust-stable-2025-03-18/lib/rustlib/aarch64-apple-darwin/lib/{libstd-9a8d4c925c11f507.rlib,libpanic_unwind-864f89af2b80e78c.rlib,libobject-41cb223da1b4bed5.rlib,libmemchr-dfdf7ff940af38f7.rlib,libaddr2line-4a8dfd2690e2969c.rlib,libgimli-ea3151e8f32ae0e2.rlib,librustc_demangle-7d770bf01ba1b6e5.rlib,libstd_detect-ebcf70da46ad6d83.rlib,libhashbrown-aef539cf033a4071.rlib,librustc_std_workspace_alloc-5808e7d6a699cb55.rlib,libminiz_oxide-e213ed6ae6f0cecb.rlib,libadler-31dd64c4c2d6f7b8.rlib,libunwind-667dd716eab04722.rlib,libcfg_if-4be5021d033c1d12.rlib,liblibc-c8bf557a67c1a091.rlib,liballoc-0b46c1dfa44283ca.rlib,librustc_std_workspace_core-b75d392d32c1a8ee.rlib,libcore-9ba39e499d30418c.rlib,libcompiler_builtins-a94b6215175cddb2.rlib}" "-liconv" "-lSystem" "-lc" "-lm" "-arch" "arm64" "-mmacosx-version-min=11.0.0" "-o" "/private/tmp/nix-build-<REDACTED>-deps-aarch64-unknown-linux-musl-0.36.1.drv-0/source/target/release/build/ring-d3b701c6fa20df45/build_script_build-d3b701c6fa20df45" "-Wl,-dead_strip" "-nodefaultlibs"
       >   = note: some arguments are omitted. use `--verbose` to show all linker arguments
       >   = note: clang-16: warning: argument unused during compilation: '-pie' [-Wunused-command-line-argument]
       >           ld: library not found for -liconv
       >           clang-16: error: linker command failed with exit code 1 (use -v to see invocation)
       >
       >
       > error: could not compile `ring` (build script) due to 1 previous error
       > warning: build failed, waiting for other jobs to finish...
       > error: linking with `cc` failed: exit status: 1
       >   |
       >   = note: env -u IPHONEOS_DEPLOYMENT_TARGET -u TVOS_DEPLOYMENT_TARGET -u XROS_DEPLOYMENT_TARGET LC_ALL="C" PATH="/nix/store/zjl03z3r8h3zycp55m41kvlqz28k5had-rust-mixed/lib/rustlib/aarch64-apple-darwin/bin:/nix/store/csjwwprnp033h6gbqrarifa0f76m61rd-libiconv-109/bin:/nix/store/9fbzrya8pqaw0lfhg9q0g3pscy2aw7kz-clang-wrapper-16.0.6/bin:/nix/store/a3cb7da0k1k4px3r6i0ar3nxr605g5yv-clang-16.0.6/bin:/nix/store/628n22773lxvj5w8pmn0wq9zag7nzd7w-coreutils-9.5/bin:/nix/store/kvx50ndpfcx73w39inrk63fnfi47wqwy-cctools-binutils-darwin-wrapper-1010.6/bin:/nix/store/5lyy560i21kd9flai0g81kwdkh82pr0m-cctools-binutils-darwin-1010.6/bin:/nix/store/2vj1s2r39dl0rb87lp41sl48pmj98170-aarch64-unknown-linux-musl-gcc-wrapper-13.3.0/bin:/nix/store/dwdqz6zcy38mbycl878dg7bkkjigcnfh-aarch64-unknown-linux-musl-gcc-13.3.0/bin:/nix/store/igdkqqq5zzhbqqbcz5jxv1fi3fw0mqah-musl-aarch64-unknown-linux-musl-1.2.5-bin/bin:/nix/store/13jcszfcc8xl1dz6phl36f3vmb7zpyid-coreutils-9.5/bin:/nix/store/6nkq4fljfki89v0mm8wf441w8y2w6say-aarch64-unknown-linux-musl-binutils-wrapper-2.43.1/bin:/nix/store/ivwqfvlzg2iry0lf1ga3bp8wc0nlwrfl-aarch64-unknown-linux-musl-binutils-2.43.1/bin:/nix/store/zjl03z3r8h3zycp55m41kvlqz28k5had-rust-mixed/bin:/nix/store/7frifb58kqclnd2a5gjarimkcily05q9-rsync-3.4.1/bin:/nix/store/w4qfr9w2pxbpz7ksy1y3rl43wiagvcpv-zstd-1.5.6-bin/bin:/nix/store/5g4pw9bc43xbhrdcjv6j4sdi1l9yldrr-zstd-1.5.6/bin:/nix/store/v8zqq0qg2hky6dzawb26ym1rdv5gs512-patchelf-0.15.0/bin:/nix/store/628n22773lxvj5w8pmn0wq9zag7nzd7w-coreutils-9.5/bin:/nix/store/70jvidma235cyw4gg80bz9vlc0d6184d-findutils-4.10.0/bin:/nix/store/gcsymgijgn2lh5d3n9k90gjjps7lcwmj-diffutils-3.10/bin:/nix/store/aqqchdzlk623ic39hcnd8irwgcpl8s2f-gnused-4.9/bin:/nix/store/vk5kab83vjh7ihvygdfbv72w838klc1d-gnugrep-3.11/bin:/nix/store/fsx7qv5fkc4r6bigcpddg88qhh24sp1i-gawk-5.3.1/bin:/nix/store/yy7y4mk7jy6imwfk8fjy9nhh53ihz7s3-gnutar-1.35/bin:/nix/store/4d1h0gzca9992cmx2ivmmjqfwl2432px-gzip-1.13/bin:/nix/store/b23vn7ragh7jwz5i3z3vhn6m00rrkiax-bzip2-1.0.8-bin/bin:/nix/store/60h3w4y3av3ss1bw6hbqivk59f9ydqxl-gnumake-4.4.1/bin:/nix/store/qzwsj5ihx6kjwikr0g77dnhcfxm1by68-bash-5.2p37/bin:/nix/store/g4s3mv5d6sk845kqspcrkp7xkaa9s5j2-patch-2.7.6/bin:/nix/store/x82gz86ymhj9mivikyf77ny9j1ajic7p-xz-5.6.3-bin/bin:/nix/store/pp6kblicnsalm9q3adbm0a51kvsxv9n0-file-5.45/bin" VSLANG="1033" ZERO_AR_DATE="1" "cc" "/private/tmp/nix-build-<REDACTED>-deps-aarch64-unknown-linux-musl-0.36.1.drv-0/rustc4SuA59/symbols.o" "<6 object files omitted>" "/private/tmp/nix-build-<REDACTED>-deps-aarch64-unknown-linux-musl-0.36.1.drv-0/source/target/release/deps/{libfs_extra-502e5a53f1648bba.rlib,libdunce-770f9b9482119578.rlib,libcmake-6630aabf95d0f2c2.rlib,libcc-2055fdd5e3d64d09.rlib,libjobserver-5a5fc4f341d03f3a.rlib,liblibc-b1fda287d7a91569.rlib,libshlex-16a10314ad0b1e79.rlib}" "/nix/store/ird7hdw2zm65s2vmj6sjkd546vzv78ax-rust-stable-2025-03-18/lib/rustlib/aarch64-apple-darwin/lib/{libstd-9a8d4c925c11f507.rlib,libpanic_unwind-864f89af2b80e78c.rlib,libobject-41cb223da1b4bed5.rlib,libmemchr-dfdf7ff940af38f7.rlib,libaddr2line-4a8dfd2690e2969c.rlib,libgimli-ea3151e8f32ae0e2.rlib,librustc_demangle-7d770bf01ba1b6e5.rlib,libstd_detect-ebcf70da46ad6d83.rlib,libhashbrown-aef539cf033a4071.rlib,librustc_std_workspace_alloc-5808e7d6a699cb55.rlib,libminiz_oxide-e213ed6ae6f0cecb.rlib,libadler-31dd64c4c2d6f7b8.rlib,libunwind-667dd716eab04722.rlib,libcfg_if-4be5021d033c1d12.rlib,liblibc-c8bf557a67c1a091.rlib,liballoc-0b46c1dfa44283ca.rlib,librustc_std_workspace_core-b75d392d32c1a8ee.rlib,libcore-9ba39e499d30418c.rlib,libcompiler_builtins-a94b6215175cddb2.rlib}" "-liconv" "-lSystem" "-lc" "-lm" "-arch" "arm64" "-mmacosx-version-min=11.0.0" "-o" "/private/tmp/nix-build-<REDACTED>-deps-aarch64-unknown-linux-musl-0.36.1.drv-0/source/target/release/build/aws-lc-sys-67c41b1bd876175d/build_script_main-67c41b1bd876175d" "-Wl,-dead_strip" "-nodefaultlibs"
       >   = note: some arguments are omitted. use `--verbose` to show all linker arguments
       >   = note: clang-16: warning: argument unused during compilation: '-pie' [-Wunused-command-line-argument]
       >           ld: library not found for -liconv
       >           clang-16: error: linker command failed with exit code 1 (use -v to see invocation)
       >
       >
       > error: could not compile `aws-lc-sys` (build script) due to 1 previous error
       For full logs, run:
         nix log /nix/store/pmvabpmdk82agba64fl2fp93pc1xydmr-<REDACTED>-deps-aarch64-unknown-linux-musl-0.36.1.drv
error: 1 dependencies of derivation '/nix/store/wb0bwmv5b65i17ijcy51hnnifnrsipwn-<REDACTED>-aarch64-unknown-linux-musl-0.36.1.drv' failed to build

I don't know why the libiconv I added to the package's nativeBuildInputs is not seen at this stage and what would I need to do to solve it.

Could I get some advice?

Thank you very much!

[ipetkov]

Hello!

Without a full reproduction the best I can do is speculate but this part of the config looks a bit suspect to me:

 craneLib = (inputs.crane.mkLib pkgs).overrideToolchain (
        _:
        with inputs.fenix.packages.${system};
        combine [
          stable.toolchain
          targets.${target}.stable.rust-std
        ]
      );

Normally .overrideToolchain calls the provided function with different pkg instances configured for cross compilation, and usually when using rust-overlay that results in picking the correctly configured compilers for things, but your config is ignoring that input entirely and always using whatever (likely, non-cross-compilation-enabled) derivations the top level fenix flake ships with.

I don't use fenix myself so I'm not entirely certain what pitfalls there might be there. My advice would be to try to get things working with rust-overlay since we have a tested example which builds with musl here: https://github.com/ipetkov/crane/blob/d02c1cdd7ec539699aa44e6ff912e15535969803/examples/cross-musl/flake.nix

Hope this helps!

[DavSanchez]

Hi @ipetkov!

Thanks for answering. I was thinking fenix could be the toolchain provider of choice for crane given how many of the examples use it. I'll try to find some time to investigate getting fenix to work, but for the moment just switching to rust-overlay as you advised worked like a charm!

Best regards