anchor.diff:    ModuleVersions = buildPerlPackage {
       name = "Module-Versions-0.02";
       src = fetchurl {
  -      url = http://cpan.metacpan.org/authors/id/T/TH/THW/Module-Versions-0.02.zip;
  +      url = mirror://cpan/authors/id/T/TH/THW/Module-Versions-0.02.zip;
         sha256 = "0g7qs6vqg91xpwg1cdy91m3kh9m1zbkzyz1qsy453b572xdscf0d";
       };
       buildInputs = [ pkgs.unzip ];
  
positive.code:   ExceptionBase = buildPerlPackage {
      name = "Exception-Base-0.25";
      src = fetchurl {
        url = http://cpan.metacpan.org/authors/id/D/DE/DEXTER/Exception-Base-0.25.tar.gz;
        sha256 = "1s2is862xba2yy633wn2nklrya36yrlwxlbpqjrv8m31xj2c8khw";
      };
      buildInputs = [ TestUnitLite ];
  
negative.code:   BitVector = buildPerlPackage {
      name = "Bit-Vector-7.3";
      src = fetchurl {
        url = mirror://cpan/authors/id/S/ST/STBEY/Bit-Vector-7.3.tar.gz;
        sha256 = "0gcg1173i1bsx2qvyw77kw90xbf03b861jc42hvq744vzc5k6xjs";
      };
      propagatedBuildInputs = [CarpClan];
  