anchor.diff:  in stdenv.lib.mapAttrs mkVariant {
     adventor = {
       displayName = "Adventor";
  -    version = "2.003";
  -    sha256 = "13wnb04z9f766ij30x8bpkn4xzv7n466g07dlbimx7qvglxl605g";
  -    outputHash = "1cz0lkk2a5fg8r8175h454va499hzln3s99dadxhh147nx1914pm";
  +    version = "2_501";
  +    sha256 = "0qjg3x0adfppyx3x33cm07ww9i9sl88xaq07m7wfip8rmyp567fn";
  +    outputHash = "117h6f02m1r54b4f1a98q5kkjchl5pv9ibm1jla6xrzhk2pchb27";
       abbreviation = "qag";
     };
     bonum = {
  
positive.code:   };
    pagella = {
      displayName = "Pagella";
      version ="2.004";
      sha256 = "0b2pjhw1ihnl951slln6d6vafjd3i6p4i947lwybvg8081qfvd9z";
      outputHash = "0c6s0r14qax3b4amvm9nffwzby8mm4p7r2hfb8yv9jzhjwa5z8rd";
      abbreviation = "qpl";
    };
    schola = {
  
negative.code: 
      installPhase = ''
        mkdir -p $out/share/fonts/opentype/
        # Pagella & Adventor are not flat archives
        test -d "${abbreviation}${version}otf" && cd "${abbreviation}${version}otf"
        cp -v *.otf $out/share/fonts/opentype/
      '';
  
  