anchor.diff:          isGNU = true;
           cc = stage4.stdenv.cc.cc;
           libc = stage4.pkgs.glibc;
  -        inherit (stage4.pkgs) binutils coreutils;
  +        inherit (stage4.pkgs) binutils coreutils gnugrep;
           name = "";
           stdenv = stage4.stdenv;
           shell = stage4.pkgs.bash + "/bin/bash";
  
positive.code:     inherit (stage0.pkgs) glibc;
      binutils = bootstrapTools;
      coreutils = bootstrapTools;
      name = "bootstrap-gcc-wrapper";
  
      # Rebuild binutils to use from stage2 onwards.
  
negative.code:   # the bootstrap.  In all stages, we build an stdenv and the package
    # set that can be built with that stdenv.
    stageFun =
      {gccPlain, glibc, binutils, coreutils, gnugrep, name, overrides ? (pkgs: {}), extraBuildInputs ? []}:
  
      let
  
  