anchor.diff:    #    (e.g. coreutils) are still from the bootstrap tools.
     stdenvLinuxBoot4 = stdenvBootFun {
       gcc = wrapGCC rec {
  +      gcc = stdenvLinuxBoot3Pkgs.gcc.gcc;
  +      libc = stdenvLinuxGlibc;
         binutils = binutils1;
         coreutils = bootstrapTools;
  -      libc = stdenvLinuxGlibc;
  -      gcc = stdenvLinuxBoot3Pkgs.gcc.gcc;
         name = "";
       };
       extraPath = [ stdenvLinuxBoot3Pkgs.xz ];
  
positive.code:   # 3) 2nd stdenv that we will use to build only Glibc.
    stdenvLinuxBoot2 = stdenvBootFun {
      gcc = wrapGCC {
        libc = bootstrapGlibc;
        binutils = binutils1;
        coreutils = bootstrapTools;
      };
      overrides = pkgs: {
        inherit (stdenvLinuxBoot1Pkgs) perl;
  
negative.code: 
    # A helper function to call gcc-wrapper.
    wrapGCC =
      { gcc, libc, binutils, coreutils, name }:
  
      lib.makeOverridable (import ../../build-support/gcc-wrapper) {
        nativeTools = false;
        nativeLibc = false;
        inherit gcc binutils coreutils libc name;
        stdenv = stdenvLinuxBoot0;
      };
  
  