anchor.diff:  
       in {
   
  -      # A Nixpkgs overlay that overrides the 'nix' and 'nix-perl'
  -      # packages.
  +      # A Nixpkgs overlay that overrides the 'nix' and
  +      # 'nix.perl-bindings' packages.
         overlay = final: prev: {
   
  -        nix = with final; with commonDeps pkgs; releaseTools.nixBuild {
  +        nix = with final; with commonDeps pkgs; (releaseTools.nixBuild {
             name = "nix";
             src = self.hydraJobs.tarball;
   
  
positive.code: 
            doInstallCheck = true;
            installCheckFlags = "sysconfdir=$(out)/etc";
          };
  
          nix-perl = with final; releaseTools.nixBuild {
            name = "nix-perl";
            src = self.hydraJobs.tarball;
  
            buildInputs =
              [ nix curl bzip2 xz pkgconfig pkgs.perl boost ]
              ++ lib.optional (stdenv.isLinux || stdenv.isDarwin) libsodium;
  
            configureFlags = ''
              --with-dbi=${perlPackages.DBI}/${pkgs.perl.libPrefix}
              --with-dbd-sqlite=${perlPackages.DBDSQLite}/${pkgs.perl.libPrefix}
            '';
  
            enableParallelBuilding = true;
  
            postUnpack = "sourceRoot=$sourceRoot/perl";
          };
  
        };
  
negative.code:         build = nixpkgs.lib.genAttrs systems (system: nixpkgsFor.${system}.nix);
  
          # Perl bindings for various platforms.
          perlBindings = nixpkgs.lib.genAttrs systems (system: nixpkgsFor.${system}.nix.perl-bindings);
  
          # Binary tarball for various platforms, containing a Nix store
          # with the closure of 'nix' package, and the second half of
  