anchor.diff:      glibc = null;
       binutils = null;
       coreutils = null;
  +    gnugrep = null;
       name = null;
   
       overrides = pkgs: {
  
positive.code:     inherit (stage1.pkgs) glibc;
      binutils = stage1.pkgs.binutils;
      coreutils = bootstrapTools;
      name = "bootstrap-gcc-wrapper";
  
      overrides = pkgs: {
  
negative.code:           cc = gccPlain;
            isGNU = true;
            libc = glibc;
            inherit binutils coreutils gnugrep;
            name = name;
            stdenv = stage0.stdenv;
          };
  