anchor.diff:    );
   
     ver1 = "120";
  -  ver2 = "0";
  +  ver2 = "1";
     ver3 = "1";
     version =   "${ver1}.${ver2}.${ver3}";
     ver_dash =  "${ver1}-${ver2}-${ver3}";
  
positive.code:     (pakName: attrs: mkPak (attrs // {inherit pakName;}))
    {
      pak64 = {
        srcPath = "${ver2_dash}/simupak64-${ver_dash}";
        sha256 = "0y5v1ncpjyhjkkznqmk13kg5d0slhjbbvg1y8q5jxhmhlkghk9q2";
      };
      "pak64.japan" = {
        srcPath = "${ver2_dash}/simupak64.japan-${ver_dash}";
        sha256 = "14swy3h4ij74bgaw7scyvmivfb5fmp21nixmhlpk3mav3wr3167i";
      };
  
      pak128 = {
        srcPath = "pak128%20for%20ST%20120%20%282.5.2%2B%20nightly%20r1560%2C%20bugfixes%29/pak128-r1560--ST120";
        sha256 = "1wd51brc4aglqi3w7s8fxgxrw0k7f653w4wbnmk83k07fwfdyf24";
      };
      "pak128.britain" = {
        srcPath = "pak128.Britain%20for%20${ver2_dash}/pak128.Britain.1.16-${ver2_dash}";
        sha256 = "1rww9rnpk22l2z3s1d7y2gmd6iwhv72s7pff8krnh7z0q386waak";
      };
      "pak128.cs" = { # note: it needs pak128 to work
        url = "mirror://sourceforge/simutrans/Pak128.CS/pak128.cz_v.0.2.1.zip";
  
negative.code:     };
      "pak128.german" = {
        url = "mirror://sourceforge/simutrans/PAK128.german/"
          + "PAK128.german_0.8_${ver1}.x/PAK128.german_0.8.0_${ver1}.x.zip";
        sha256 = "1a8pc88vi59zlvff9i1f8nphdmisqmgg03qkdvrf5ks46aw8j6s5";
      };
  
      /* This release contains accented filenames that prevent unzipping.
  