core/pkgs/stdenv/linux/default.nix

# This file constructs the standard build environment for the
# Linux platform.  It's completely pure; that is, it relies on no
# external (non-Nix) tools, such as /usr/bin/gcc, and it contains a C
# compiler and linker that do not search in default locations,
# ensuring purity of components produced by it.
#
# It starts from prebuilt seed bootstrapFiles and creates a series of
# nixpkgs instances (stages) to gradually rebuild stdenv, which
# is used to build all other packages (including the bootstrapFiles).
#
# Goals of the bootstrap process:
# 1. final stdenv must not reference any of the bootstrap files.
# 2. final stdenv must not contain any of the bootstrap files.
# 3. final stdenv must not contain any of the files directly
#    generated by the bootstrap code generators (assembler, linker,
#    compiler).
#
# These goals ensure that final packages and final stdenv are built
# exclusively using nixpkgs package definitions and don't depend
# on bootstrapTools (via direct references, inclusion
# of copied code, or code compiled directly by bootstrapTools).
#
# Stages are described below along with their definitions.
#
# Debugging stdenv dependency graph:
# An useful tool to explore dependencies across stages is to use
# '__bootPackages' attribute of 'stdenv. Examples of last 3 stages:
# - stdenv
# - stdenv.__bootPackages.stdenv
# - stdenv.__bootPackages.stdenv.__bootPackages.stdenv
# - ... and so on.
#
# To explore build-time dependencies in graphical form one can use
# the following:
#     $ nix-store --query --graph $(nix-instantiate -A stdenv) |
#         grep -P -v '[.]sh|[.]patch|bash|[.]tar' | # avoid clutter
#         dot -Tsvg > stdenv-final.svg
#
# To find all the packages built by a particular stdenv instance:
#    $ for stage in 0 1 2 3 4; do
#      echo "stage${stage} used in:"
#      nix-store --query --graph $(nix-instantiate -A stdenv) |
#          grep -P ".*bootstrap-stage${stage}-stdenv.*->.*" |
#          sed 's/"[0-9a-z]\{32\}-/"/g'
#      done
#
# To verify which stdenv was used to build a given final package:
#     $ nix-store --query --graph $(nix-instantiate -A stdenv) |
#       grep -P -v '[.]sh|[.]patch|bash|[.]tar' |
#       grep -P '.*stdenv.*->.*glibc-2'
#     "...-bootstrap-stage2-stdenv-linux.drv" -> "...-glibc-2.35-224.drv";
#
# For a TUI (rather than CLI) view, you can use:
#
#     $ nix-tree --derivation $(nix-instantiate -A stdenv)
{ lib, localSystem, crossSystem, config

, bootstrapFiles ? let
  table = {
    glibc = {
      i686-linux = import ./bootstrap-files/i686-unknown-linux-gnu.nix;
      x86_64-linux = import ./bootstrap-files/x86_64-unknown-linux-gnu.nix;
      armv5tel-linux =
        import ./bootstrap-files/armv5tel-unknown-linux-gnueabi.nix;
      armv6l-linux =
        import ./bootstrap-files/armv6l-unknown-linux-gnueabihf.nix;
      armv7l-linux =
        import ./bootstrap-files/armv7l-unknown-linux-gnueabihf.nix;
      aarch64-linux = import ./bootstrap-files/aarch64-unknown-linux-gnu.nix;
      mipsel-linux = import ./bootstrap-files/mipsel-unknown-linux-gnu.nix;
      mips64el-linux = import (if localSystem.isMips64n32 then
        ./bootstrap-files/mips64el-unknown-linux-gnuabin32.nix
      else
        ./bootstrap-files/mips64el-unknown-linux-gnuabi64.nix);
      powerpc64-linux =
        import ./bootstrap-files/powerpc64-unknown-linux-gnuabielfv2.nix;
      powerpc64le-linux =
        import ./bootstrap-files/powerpc64le-unknown-linux-gnu.nix;
      riscv64-linux = import ./bootstrap-files/riscv64-unknown-linux-gnu.nix;
    };
    musl = {
      aarch64-linux = import ./bootstrap-files/aarch64-unknown-linux-musl.nix;
      armv6l-linux =
        import ./bootstrap-files/armv6l-unknown-linux-musleabihf.nix;
      x86_64-linux = import ./bootstrap-files/x86_64-unknown-linux-musl.nix;
    };
  };

  # Try to find an architecture compatible with our current system. We
  # just try every bootstrap we’ve got and test to see if it is
  # compatible with or current architecture.
  getCompatibleTools = lib.foldl (v: system:
    if v != null then
      v
    else if localSystem.canExecute
    (lib.systems.elaborate { inherit system; }) then
      archLookupTable.${system}
    else
      null) null (lib.attrNames archLookupTable);

  archLookupTable = table.${localSystem.libc} or (throw
    "unsupported libc for the pure Linux stdenv");
  files =
    archLookupTable.${localSystem.system} or (if getCompatibleTools != null then
      getCompatibleTools
    else
      (throw "unsupported platform for the pure Linux stdenv"));
in files }:

assert crossSystem == localSystem;

let
  inherit (localSystem) system;

  isFromNixpkgs = pkg: !(isFromBootstrapFiles pkg);
  isFromBootstrapFiles = pkg: pkg.passthru.isFromBootstrapFiles or false;
  isBuiltByNixpkgsCompiler = pkg:
    isFromNixpkgs pkg && isFromNixpkgs pkg.stdenv.cc.cc;
  isBuiltByBootstrapFilesCompiler = pkg:
    isFromNixpkgs pkg && isFromBootstrapFiles pkg.stdenv.cc.cc;

  commonGccOverrides = {
    # Use a deterministically built compiler
    # see https://github.com/NixOS/nixpkgs/issues/108475 for context
    reproducibleBuild = true;
    profiledCompiler = false;

    # It appears that libcc1 (which is not a g++ plugin; it is a gdb plugin) gets linked against
    # the libstdc++ from the compiler that *built* g++, not the libstdc++ which was just built.
    # This causes a reference chain from stdenv to the bootstrapFiles:
    #
    #   stdenv -> gcc-lib -> xgcc-lib -> bootstrapFiles
    #
    disableGdbPlugin = true;
  };

  commonPreHook = ''
    export NIX_ENFORCE_PURITY="''${NIX_ENFORCE_PURITY-1}"
    export NIX_ENFORCE_NO_NATIVE="''${NIX_ENFORCE_NO_NATIVE-1}"
  '';

  # The bootstrap process proceeds in several steps.

  # Create a standard environment by downloading pre-built binaries of
  # coreutils, GCC, etc.

  # Download and unpack the bootstrap tools (coreutils, GCC, Glibc, ...).
  bootstrapTools = (import (if localSystem.libc == "musl" then
    ./bootstrap-tools-musl
  else
    ./bootstrap-tools) {
      inherit system bootstrapFiles;
      extraAttrs = lib.optionalAttrs config.contentAddressedByDefault {
        __contentAddressed = true;
        outputHashAlgo = "sha256";
        outputHashMode = "recursive";
      };
    }) // {
      passthru.isFromBootstrapFiles = true;
    };

  getLibc = stage: stage.${localSystem.libc};

  # This function builds the various standard environments used during
  # the bootstrap.  In all stages, we build an stdenv and the package
  # set that can be built with that stdenv.
  stageFun = prevStage:
    { name, overrides ? (self: super: { }), extraNativeBuildInputs ? [ ] }:

    let

      thisStdenv = import ../generic lib {
        name = "${name}-stdenv-linux";
        buildPlatform = localSystem;
        hostPlatform = localSystem;
        targetPlatform = localSystem;
        inherit config extraNativeBuildInputs;
        preHook = ''
          # Don't patch #!/interpreter because it leads to retained
          # dependencies on the bootstrapTools in the final stdenv.
          dontPatchShebangs=1
          ${commonPreHook}
        '';
        shell = "${bootstrapTools}/bin/bash";
        initialPath = [ bootstrapTools ];

        fetchurlBoot =
          import ../../build-support/fetchurl/boot.nix { inherit system; };

        cc = if prevStage.gcc-unwrapped == null then
          null
        else
          (lib.makeOverridable (import ../../build-support/cc-wrapper) {
            name = "${name}-gcc-wrapper";
            nativeTools = false;
            nativeLibc = false;
            expand-response-params = lib.optionalString
              (prevStage.stdenv.hasCC or false && prevStage.stdenv.cc
                != "/dev/null") prevStage.expand-response-params;
            cc = prevStage.gcc-unwrapped;
            bintools = prevStage.binutils;
            isGNU = true;
            libc = getLibc prevStage;
            inherit lib;
            inherit (prevStage) coreutils gnugrep;
            stdenvNoCC = prevStage.ccWrapperStdenv;
            fortify-headers = prevStage.fortify-headers;
            runtimeShell = prevStage.ccWrapperStdenv.shell;
          }).overrideAttrs (a:
            lib.optionalAttrs
            (prevStage.gcc-unwrapped.passthru.isXgcc or false) {
              # This affects only `xgcc` (the compiler which compiles the final compiler).
              postFixup = (a.postFixup or "") + ''
                echo "--sysroot=${
                  lib.getDev (getLibc prevStage)
                }" >> $out/nix-support/cc-cflags
              '';
            });

        overrides = self: super:
          (overrides self super) // {
            fetchurl = thisStdenv.fetchurlBoot;
          };
      };

    in {
      inherit config;
      stdenv = thisStdenv;
    };

in assert bootstrapTools.passthru.isFromBootstrapFiles or false; # sanity check
[

  ({ }: {
    __raw = true;

    gcc-unwrapped = null;
    binutils = null;
    coreutils = null;
    gnugrep = null;
  })

  # Build a dummy stdenv with no GCC or working fetchurl.  This is
  # because we need a stdenv to build the GCC wrapper and fetchurl.
  (prevStage:
    stageFun prevStage {
      name = "bootstrap-stage0";

      overrides = self: super: {
        # We thread stage0's stdenv through under this name so downstream stages
        # can use it for wrapping gcc too. This way, downstream stages don't need
        # to refer to this stage directly, which violates the principle that each
        # stage should only access the stage that came before it.
        ccWrapperStdenv = self.stdenv;
        # The Glibc include directory cannot have the same prefix as the
        # GCC include directory, since GCC gets confused otherwise (it
        # will search the Glibc headers before the GCC headers).  So
        # create a dummy Glibc here, which will be used in the stdenv of
        # stage1.
        ${localSystem.libc} = self.stdenv.mkDerivation {
          pname = "bootstrap-stage0-${localSystem.libc}";
          strictDeps = true;
          version = "bootstrapFiles";
          enableParallelBuilding = true;
          buildCommand = ''
            mkdir -p $out
            ln -s ${bootstrapTools}/lib $out/lib
          '' + lib.optionalString (localSystem.libc == "glibc") ''
            ln -s ${bootstrapTools}/include-glibc $out/include
          '' + lib.optionalString (localSystem.libc == "musl") ''
            ln -s ${bootstrapTools}/include-libc $out/include
          '';
          passthru.isFromBootstrapFiles = true;
        };
        gcc-unwrapped = bootstrapTools;
        binutils = import ../../build-support/bintools-wrapper {
          name = "bootstrap-stage0-binutils-wrapper";
          nativeTools = false;
          nativeLibc = false;
          expand-response-params = "";
          libc = getLibc self;
          inherit lib;
          inherit (self) stdenvNoCC coreutils gnugrep;
          bintools = bootstrapTools;
          runtimeShell = "${bootstrapTools}/bin/bash";
        };
        coreutils = bootstrapTools;
        gnugrep = bootstrapTools;
      };
    })

  # Create the first "real" standard environment.  This one consists
  # of bootstrap tools only, and a minimal Glibc to keep the GCC
  # configure script happy.
  #
  # For clarity, we only use the previous stage when specifying these
  # stages.  So stageN should only ever have references for stage{N-1}.
  #
  # If we ever need to use a package from more than one stage back, we
  # simply re-export those packages in the middle stage(s) using the
  # overrides attribute and the inherit syntax.
  (prevStage:
    # previous stage0 stdenv:
    assert isFromBootstrapFiles prevStage.binutils.bintools;
    assert isFromBootstrapFiles prevStage."${localSystem.libc}";
    assert isFromBootstrapFiles prevStage.gcc-unwrapped;
    assert isFromBootstrapFiles prevStage.coreutils;
    assert isFromBootstrapFiles prevStage.gnugrep;
    stageFun prevStage {
      name = "bootstrap-stage1";

      # Rebuild binutils to use from stage2 onwards.
      overrides = self: super: {
        binutils-unwrapped =
          super.binutils-unwrapped.override { enableGold = false; };
        inherit (prevStage)
          ccWrapperStdenv gcc-unwrapped coreutils gnugrep binutils;

        ${localSystem.libc} = getLibc prevStage;

        # A threaded perl build needs glibc/libpthread_nonshared.a,
        # which is not included in bootstrapTools, so disable threading.
        # This is not an issue for the final stdenv, because this perl
        # won't be included in the final stdenv and won't be exported to
        # top-level pkgs as an override either.
        perl = super.perl.override {
          enableThreading = false;
          enableCrypt = false;
        };
      };

      # `gettext` comes with obsolete config.sub/config.guess that don't recognize LoongArch64.
      extraNativeBuildInputs =
        [ prevStage.updateAutotoolsGnuConfigScriptsHook ];
    })

  # First rebuild of gcc; this is linked against all sorts of junk
  # from the bootstrap-files, but we only care about the code that
  # this compiler *emits*.  The `gcc` binary produced in this stage
  # is not part of the final stdenv.
  (prevStage:
    assert isBuiltByBootstrapFilesCompiler prevStage.binutils-unwrapped;
    assert isFromBootstrapFiles prevStage."${localSystem.libc}";
    assert isFromBootstrapFiles prevStage.gcc-unwrapped;
    assert isFromBootstrapFiles prevStage.coreutils;
    assert isFromBootstrapFiles prevStage.gnugrep;
    assert isBuiltByBootstrapFilesCompiler prevStage.patchelf;
    stageFun prevStage {
      name = "bootstrap-stage-xgcc";
      overrides = self: super: {
        inherit (prevStage)
          ccWrapperStdenv coreutils gnugrep gettext bison texinfo zlib gnum4
          perl patchelf;
        ${localSystem.libc} = getLibc prevStage;
        gmp = super.gmp.override { cxx = false; };
        # This stage also rebuilds binutils which will of course be used only in the next stage.
        # We inherit this until stage3, in stage4 it will be rebuilt using the adjacent bash/runtimeShell pkg.
        # TODO(@sternenseemann): Can we already build the wrapper with the actual runtimeShell here?
        # Historically, the wrapper didn't use runtimeShell, so the used shell had to be changed explicitly
        # (or stdenvNoCC.shell would be used) which happened in stage4.
        binutils = super.binutils.override {
          runtimeShell = "${bootstrapTools}/bin/bash";
        };
        gcc-unwrapped = (super.gcc-unwrapped.override (commonGccOverrides // {
          # The most logical name for this package would be something like
          # "gcc-stage1".  Unfortunately "stage" is already reserved for the
          # layers of stdenv, so using "stage" in the name of this package
          # would cause massive confusion.
          #
          # Gcc calls its "stage1" compiler `xgcc` (--disable-bootstrap results
          # in `xgcc` being copied to $prefix/bin/gcc).  So we imitate that.
          #
          name = "xgcc";

          # xgcc uses ld linked against nixpkgs' glibc and gcc built
          # against bootstrapTools glibc. We can't allow loading
          #   $out/libexec/gcc/x86_64-unknown-linux-gnu/13.0.1/liblto_plugin.so
          # to mix libc.so:
          #   ...-binutils-patchelfed-ld-2.40/bin/ld: ...-xgcc-13.0.0/libexec/gcc/x86_64-unknown-linux-gnu/13.0.1/liblto_plugin.so:
          #     error loading plugin: ...-bootstrap-tools/lib/libpthread.so.0: undefined symbol: __libc_vfork, version GLIBC_PRIVATE
          enableLTO = false;
        })).overrideAttrs (a: {

          # This signals to cc-wrapper (as overridden above in this file) to add `--sysroot`
          # to `$out/nix-support/cc-cflags`.
          passthru = a.passthru // { isXgcc = true; };

          # Gcc will look for the C library headers in
          #
          #    ${with_build_sysroot}${native_system_header_dir}
          #
          # The ordinary gcc expression sets `--with-build-sysroot=/` and sets
          # `native-system-header-dir` to `"${lib.getDev stdenv.cc.libc}/include`.
          #
          # Unfortunately the value of "--with-native-system-header-dir=" gets "burned in" to the
          # compiler, and it is quite difficult to get the compiler to change or ignore it
          # afterwards.  On the other hand, the `sysroot` is very easy to change; you can just pass
          # a `--sysroot` flag to `gcc`.
          #
          # So we override the expression to remove the default settings for these flags, and
          # replace them such that the concatenated value will be the same as before, but we split
          # the value between the two variables differently: `--native-system-header-dir=/include`,
          # and `--with-build-sysroot=${lib.getDev stdenv.cc.libc}`.
          #
          configureFlags = (a.configureFlags or [ ]) ++ [
            "--with-native-system-header-dir=/include"
            "--with-build-sysroot=${lib.getDev self.stdenv.cc.libc}"
          ];

          # This is a separate phase because gcc assembles its phase scripts
          # in bash instead of nix (we should fix that).
          preFixupPhases = (a.preFixupPhases or [ ]) ++ [ "preFixupXgccPhase" ];

          # This is needed to prevent "error: cycle detected in build of '...-xgcc-....drv'
          # in the references of output 'lib' from output 'out'"
          preFixupXgccPhase = ''
            find $lib/lib/ -name \*.so\* -exec patchelf --shrink-rpath {} \; || true
          '';
        });
      };

      # `gettext` comes with obsolete config.sub/config.guess that don't recognize LoongArch64.
      extraNativeBuildInputs =
        [ prevStage.updateAutotoolsGnuConfigScriptsHook ];
    })

  # 2nd stdenv that contains our own rebuilt binutils and is used for
  # compiling our own Glibc.
  #
  (prevStage:
    # previous stage1 stdenv:
    assert isBuiltByBootstrapFilesCompiler prevStage.binutils-unwrapped;
    assert isFromBootstrapFiles prevStage."${localSystem.libc}";
    assert isBuiltByBootstrapFilesCompiler prevStage.gcc-unwrapped;
    assert isFromBootstrapFiles prevStage.coreutils;
    assert isFromBootstrapFiles prevStage.gnugrep;
    assert isBuiltByBootstrapFilesCompiler prevStage.patchelf;
    stageFun prevStage {
      name = "bootstrap-stage2";

      overrides = self: super: {
        inherit (prevStage)
          ccWrapperStdenv gettext gcc-unwrapped coreutils gnugrep perl gnum4
          bison texinfo which;
        dejagnu = super.dejagnu.overrideAttrs (a: { doCheck = false; });

        # We need libidn2 and its dependency libunistring as glibc dependency.
        # To avoid the cycle, we build against bootstrap libc, nuke references,
        # and use the result as input for our final glibc.  We also pass this pair
        # through, so the final package-set uses exactly the same builds.
        libunistring = super.libunistring.overrideAttrs (attrs: {
          postFixup = attrs.postFixup or "" + ''
            ${self.nukeReferences}/bin/nuke-refs "$out"/lib/lib*.so.*.*
          '';
          # Apparently iconv won't work with bootstrap glibc, but it will be used
          # with glibc built later where we keep *this* build of libunistring,
          # so we need to trick it into supporting libiconv.
          env = attrs.env or { } // { am_cv_func_iconv_works = "yes"; };
        });
        libidn2 = super.libidn2.overrideAttrs (attrs: {
          postFixup = attrs.postFixup or "" + ''
            ${self.nukeReferences}/bin/nuke-refs -e '${
              lib.getLib self.libunistring
            }' \
              "$out"/lib/lib*.so.*.*
          '';
        });

        # This also contains the full, dynamically linked, final Glibc.
        binutils = prevStage.binutils.override {
          # Rewrap the binutils with the new glibc, so both the next
          # stage's wrappers use it.
          libc = getLibc self;

          # Unfortunately, when building gcc in the next stage, its LTO plugin
          # would use the final libc but `ld` would use the bootstrap one,
          # and that can fail to load.  Therefore we upgrade `ld` to use newer libc;
          # apparently the interpreter needs to match libc, too.
          bintools = self.stdenvNoCC.mkDerivation {
            pname = prevStage.bintools.bintools.pname + "-patchelfed-ld";
            inherit (prevStage.bintools.bintools) version;
            passthru = {
              inherit (prevStage.bintools.passthru) isFromBootstrapFiles;
            };
            enableParallelBuilding = true;
            dontUnpack = true;
            dontBuild = true;
            strictDeps = true;
            # We wouldn't need to *copy* all, but it's easier and the result is temporary anyway.
            installPhase = ''
              mkdir -p "$out"/bin
              cp -a '${prevStage.bintools.bintools}'/bin/* "$out"/bin/
              chmod +w "$out"/bin/ld.bfd
              patchelf --set-interpreter '${getLibc self}'/lib/ld*.so.? \
                --set-rpath "${
                  getLibc self
                }/lib:$(patchelf --print-rpath "$out"/bin/ld.bfd)" \
                "$out"/bin/ld.bfd
            '';
          };
        };

        # TODO(amjoseph): It is not yet entirely clear why this is necessary.
        # Something strange is going on with xgcc and libstdc++ on pkgsMusl.
        patchelf = super.patchelf.overrideAttrs (previousAttrs:
          lib.optionalAttrs super.stdenv.hostPlatform.isMusl {
            NIX_CFLAGS_COMPILE = (previousAttrs.NIX_CFLAGS_COMPILE or "")
              + " -static-libstdc++";
          });

      };

      # `gettext` comes with obsolete config.sub/config.guess that don't recognize LoongArch64.
      # `libtool` comes with obsolete config.sub/config.guess that don't recognize Risc-V.
      extraNativeBuildInputs =
        [ prevStage.updateAutotoolsGnuConfigScriptsHook ];
    })

  # Construct a third stdenv identical to the 2nd, except that this
  # one uses the rebuilt Glibc from stage2.  It still uses the recent
  # binutils and rest of the bootstrap tools, including GCC.
  (prevStage:
    # previous stage2 stdenv:
    assert isBuiltByNixpkgsCompiler prevStage.binutils-unwrapped;
    assert isBuiltByNixpkgsCompiler prevStage.${localSystem.libc};
    assert isBuiltByBootstrapFilesCompiler prevStage.gcc-unwrapped;
    assert isFromBootstrapFiles prevStage.coreutils;
    assert isFromBootstrapFiles prevStage.gnugrep;
    assert isBuiltByNixpkgsCompiler prevStage.patchelf;
    assert lib.all isBuiltByNixpkgsCompiler
      (with prevStage; [ gmp isl_0_20 libmpc mpfr ]);
    stageFun prevStage {
      name = "bootstrap-stage3";

      overrides = self: super:
        rec {
          inherit (prevStage)
            ccWrapperStdenv binutils coreutils gnugrep gettext perl patchelf
            linuxHeaders gnum4 bison libidn2 libunistring libxcrypt;
          # We build a special copy of libgmp which doesn't use libstdc++, because
          # xgcc++'s libstdc++ references the bootstrap-files (which is what
          # compiles xgcc++).
          gmp = super.gmp.override { cxx = false; };
        } // {
          ${localSystem.libc} = getLibc prevStage;
          gcc-unwrapped = (super.gcc-unwrapped.override (commonGccOverrides // {
            inherit (prevStage) which;
          })).overrideAttrs (a: {
            # so we can add them to allowedRequisites below
            passthru = a.passthru // { inherit (self) gmp mpfr libmpc isl; };
          });
        };
      extraNativeBuildInputs = [
        prevStage.patchelf
        # Many tarballs come with obsolete config.sub/config.guess that don't recognize aarch64.
        prevStage.updateAutotoolsGnuConfigScriptsHook
      ];
    })

  # Construct a fourth stdenv that uses the new GCC.  But coreutils is
  # still from the bootstrap tools.
  #
  (prevStage:
    # previous stage3 stdenv:
    assert isBuiltByNixpkgsCompiler prevStage.binutils-unwrapped;
    assert isBuiltByNixpkgsCompiler prevStage.${localSystem.libc};
    assert isBuiltByNixpkgsCompiler prevStage.gcc-unwrapped;
    assert isFromBootstrapFiles prevStage.coreutils;
    assert isFromBootstrapFiles prevStage.gnugrep;
    assert isBuiltByNixpkgsCompiler prevStage.patchelf;
    stageFun prevStage {
      name = "bootstrap-stage4";

      overrides = self: super: {
        # Zlib has to be inherited and not rebuilt in this stage,
        # because gcc (since JAR support) already depends on zlib, and
        # then if we already have a zlib we want to use that for the
        # other purposes (binutils and top-level pkgs) too.
        inherit (prevStage)
          gettext gnum4 bison perl texinfo zlib linuxHeaders libidn2
          libunistring;
        ${localSystem.libc} = getLibc prevStage;
        # Since this is the first fresh build of binutils since stage2, our own runtimeShell will be used.
        binutils = super.binutils.override {
          # Build expand-response-params with last stage like below
          inherit (prevStage) expand-response-params;
        };

        # To allow users' overrides inhibit dependencies too heavy for
        # bootstrap, like guile: https://github.com/NixOS/nixpkgs/issues/181188
        gnumake = super.gnumake.override { inBootstrap = true; };

        gcc = lib.makeOverridable (import ../../build-support/cc-wrapper) {
          nativeTools = false;
          nativeLibc = false;
          isGNU = true;
          inherit (prevStage) expand-response-params;
          cc = prevStage.gcc-unwrapped;
          bintools = self.binutils;
          libc = getLibc self;
          inherit lib;
          inherit (self) stdenvNoCC coreutils gnugrep runtimeShell;
          fortify-headers = self.fortify-headers;
        };
      };
      extraNativeBuildInputs = [
        prevStage.patchelf
        prevStage.xz
        # Many tarballs come with obsolete config.sub/config.guess that don't recognize aarch64.
        prevStage.updateAutotoolsGnuConfigScriptsHook
      ];
    })

  # Construct the final stdenv.  It uses the Glibc and GCC, and adds
  # in a new binutils that doesn't depend on bootstrap-tools, as well
  # as dynamically linked versions of all other tools.
  #
  # When updating stdenvLinux, make sure that the result has no
  # dependency (`nix-store -qR') on bootstrapTools or the first
  # binutils built.
  #
  (prevStage:
    # previous stage4 stdenv; see stage3 comment regarding gcc,
    # which applies here as well.
    assert isBuiltByNixpkgsCompiler prevStage.binutils-unwrapped;
    assert isBuiltByNixpkgsCompiler prevStage.${localSystem.libc};
    assert isBuiltByNixpkgsCompiler prevStage.gcc-unwrapped;
    assert isBuiltByNixpkgsCompiler prevStage.coreutils;
    assert isBuiltByNixpkgsCompiler prevStage.gnugrep;
    assert isBuiltByNixpkgsCompiler prevStage.patchelf; {
      inherit config;
      stdenv = import ../generic lib rec {
        name = "stdenv-linux";

        buildPlatform = localSystem;
        hostPlatform = localSystem;
        targetPlatform = localSystem;
        inherit config;

        preHook = commonPreHook;

        initialPath =
          ((import ../generic/common-path.nix) { pkgs = prevStage; });

        extraNativeBuildInputs = [
          prevStage.patchelf
          # Many tarballs come with obsolete config.sub/config.guess that don't recognize aarch64.
          prevStage.updateAutotoolsGnuConfigScriptsHook
        ];

        cc = prevStage.gcc;

        shell = cc.shell;

        inherit (prevStage.stdenv) fetchurlBoot;

        extraAttrs = {
          inherit bootstrapTools;
          shellPackage = prevStage.bash;
        };

        disallowedRequisites = [ bootstrapTools.out ];

        # Mainly avoid reference to bootstrap tools
        allowedRequisites = with prevStage;
          with lib;
          # Simple executable tools
          concatMap (p: [ (getBin p) (getLib p) ]) [
            gzip
            bzip2
            xz
            bash
            binutils.bintools
            coreutils
            diffutils
            findutils
            gawk
            gmp
            gnumake
            gnused
            gnutar
            gnugrep
            gnupatch
            patchelf
            ed
            file
          ]
          # Library dependencies
          ++ map getLib ([ attr acl zlib gnugrep.pcre2 libidn2 libunistring ]
            ++ lib.optional (gawk.libsigsegv != null) gawk.libsigsegv)
          # More complicated cases
          ++ (map (x: getOutput x (getLibc prevStage)) [ "out" "dev" "bin" ])
          ++ [
            linuxHeaders # propagated from .dev
            binutils
            gcc
            gcc.cc
            gcc.cc.lib
            gcc.expand-response-params # != (prevStage.)expand-response-params
            gcc.cc.libgcc
            glibc.passthru.libgcc
          ] ++ lib.optionals (localSystem.libc == "musl") [ fortify-headers ]
          ++ [
            prevStage.updateAutotoolsGnuConfigScriptsHook
            prevStage.gnu-config
          ] ++ (with gcc-unwrapped.passthru; [ gmp libmpc mpfr isl ]);

        overrides = self: super:
          {
            inherit (prevStage)
              gzip bzip2 xz bash coreutils diffutils findutils gawk gnused
              gnutar gnugrep gnupatch patchelf attr acl zlib libunistring;
            inherit (prevStage.gnugrep) pcre2;
            ${localSystem.libc} = getLibc prevStage;

            # Hack: avoid libidn2.{bin,dev} referencing bootstrap tools.  There's a logical cycle.
            libidn2 =
              import ../../by-name/li/libidn2/no-bootstrap-reference.nix {
                inherit lib;
                inherit (prevStage) libidn2;
                inherit (self) stdenv runCommandLocal patchelf libunistring;
              };

            gnumake = super.gnumake.override { inBootstrap = false; };
          } // lib.optionalAttrs (super.stdenv.targetPlatform == localSystem) {
            # Need to get rid of these when cross-compiling.
            inherit (prevStage) binutils binutils-unwrapped;
            gcc = cc;
          };
      };
    })

  # This "no-op" stage is just a place to put the assertions about stage5.
  (prevStage:
    # previous stage5 stdenv; see stage3 comment regarding gcc,
    # which applies here as well.
    assert isBuiltByNixpkgsCompiler prevStage.binutils-unwrapped;
    assert isBuiltByNixpkgsCompiler prevStage.${localSystem.libc};
    assert isBuiltByNixpkgsCompiler prevStage.gcc-unwrapped;
    assert isBuiltByNixpkgsCompiler prevStage.coreutils;
    assert isBuiltByNixpkgsCompiler prevStage.gnugrep;
    assert isBuiltByNixpkgsCompiler prevStage.patchelf; {
      inherit (prevStage) config stdenv;
    })
]