anchor.diff:        overrides = pkgs: (lib.mapAttrs (n: _: throw "stage3Pkgs is missing package definition for `${n}`") pkgs) // {
           pkgs = stage3Pkgs;
           inherit (stage1Pkgs) glibc linux-headers;
  -        inherit (stage2Pkgs) m4 gnum4 which gettext;
  +        inherit (stage2Pkgs) m4 gnum4 which;
           inherit (pkgs) stdenv xz zlib attr acl gmp coreutils binutils
  -          gpm ncurses readline bash libnghttp2 cryptodevHeaders
  +          gpm ncurses readline bash libnghttp2 cryptodevHeaders gettext
             openssl c-ares curl libsigsegv pcre findutils diffutils gnused gnugrep
             gawk gnutar gzip bzip2 gnumake gnupatch pkgconf pkgconfig patchelf;
   
  
positive.code:   };
  
    # This is the second package set using the final glibc and bootstrap tools.
    # This stage is used for building the final gcc.
    # Propagates stage1 glibc and linux-headers.
    stage2Pkgs = allPackages rec {
      inherit targetSystem hostSystem config;
  
negative.code: 
      overrides = pkgs: {
        inherit (stage1Pkgs) glibc linux-headers;
        inherit (stage2Pkgs) m4 gnum4 which;
        inherit (stage3Pkgs) gcc xz zlib attr acl gmp coreutils binutils
          gpm ncurses readline bash libnghttp2 cryptodevHeaders gettext
          openssl c-ares curl libsigsegv pcre findutils diffutils gnused gnugrep
          gawk gnutar gzip bzip2 gnumake gnupatch pkgconf pkgconfig patchelf;
      };
  