anchor.diff:    inherit (python2.pkgs) fonttools;
   
     common =
  -    {version, url, sha256, buildInputs}:
  +    {version, url, sha256, buildInputs, postPatch ? null, outputHash}:
       stdenv.mkDerivation rec {
         name = "liberation-fonts-${version}";
         src = fetchurl {
           inherit url sha256;
         };
   
  -      inherit buildInputs;
  +      inherit buildInputs postPatch;
   
         installPhase = ''
           mkdir -p $out/share/fonts/truetype
           cp -v $( find . -name '*.ttf') $out/share/fonts/truetype
   
  -        mkdir -p "$out/doc/${name}"
  -        cp -v AUTHORS ChangeLog COPYING License.txt README "$out/doc/${name}" || true
  +        mkdir -p "$out/share/doc/${name}"
  +        cp -v AUTHORS ChangeLog COPYING License.txt README "$out/share/doc/${name}" || true
         '';
  +
  +      outputHashAlgo = "sha256";
  +      outputHashMode = "recursive";
  +      inherit outputHash;
   
         meta = with stdenv.lib; {
           description = "Liberation Fonts, replacements for Times New Roman, Arial, and Courier New";
  
positive.code:         '';
  
          license = licenses.ofl;
          homepage = https://fedorahosted.org/liberation-fonts/;
          maintainers = [
            maintainers.raskin
          ];
  
negative.code: in {
    liberation_ttf_v1_from_source = common rec {
      version = "1.07.4";
      url = "https://releases.pagure.org/liberation-fonts/liberation-fonts-${version}.tar.gz";
      sha256 = "01jlg88q2s6by7qv6fmnrlx0lwjarrjrpxv811zjz6f2im4vg65d";
      buildInputs = [ fontforge ];
      outputHash = "1q102rmg4004p74f8m4y8a6iklmnva0q39sq260jsq3lhcfypg7p";
    };
    liberation_ttf_v1_binary = common rec {
      version = "1.07.4";
      url = "https://releases.pagure.org/liberation-fonts/liberation-fonts-ttf-${version}.tar.gz";
      sha256 = "0p7frz29pmjlk2d0j2zs5kfspygwdnpzxkb2hwzcfhrafjvf59v1";
      buildInputs = [ ];
      outputHash = "12gwb9b4ij9d93ky4c9ykgp03fqr62axy37pds88q7y6zgciwkab";
    };
    liberation_ttf_v2_from_source = common rec {
      version = "2.00.1";
      url = "https://releases.pagure.org/liberation-fonts/liberation-fonts-${version}.tar.gz";
      sha256 = "1ymryvd2nw4jmw4w5y1i3ll2dn48rpkqzlsgv7994lk6qc9cdjvs";
      buildInputs = [ fontforge fonttools ];
      postPatch = ''
        substituteInPlace scripts/setisFixedPitch-fonttools.py --replace \
          'font = ttLib.TTFont(fontfile)' \
          'font = ttLib.TTFont(fontfile, recalcTimestamp=False)'
      '';
      outputHash = "0nldgawm0a6lpn86w4w3rzx01ns3ph09ar1knq1g4jkxc8ci5rqn";
    };
    liberation_ttf_v2_binary = common rec {
      version = "2.00.1";
      url = "https://releases.pagure.org/liberation-fonts/liberation-fonts-ttf-${version}.tar.gz";
      sha256 = "010m4zfqan4w04b6bs9pm3gapn9hsb18bmwwgp2p6y6idj52g43q";
      buildInputs = [ ];
      outputHash = "19jky9li345zsig9pcb0rnlsjqqclh7r60vbi4pwh16f14850gpk";
    };
  }
  