anchor.diff:      [ "color"              "black"              ]
       [ "OpenMoji-Color.ttf" "OpenMoji-Black.ttf" ]
       variant;
  +  scfbuildOptions = stdenv.lib.optionalString (variant == "black") "--glyph-only";
  +
  +  # We have to use their scfbuild fork:
  +  # https://github.com/hfg-gmuend/openmoji/tree/master/font#setup
  +  scfbuildPatched = scfbuild.overrideAttrs (old: {
  +    src = fetchFromGitHub {
  +      owner = "b-g";
  +      repo = "scfbuild";
  +      rev = "880f690332fc9cc4dee0790921d331f13bd5acaa";
  +      sha256 = "0d61gn69hgxn17jvs69xpblq9z1l85aymbrn6jjwqamhpcl42c04";
  +    };
  +    propagatedBuildInputs = old.propagatedBuildInputs ++ [ python3Packages.lxml ];
  +  });
   
   in stdenv.mkDerivation rec {
     pname = "openmoji";
  -  version = "12.1.0";
  +  version = "12.4.0";
   
     src = fetchFromGitHub {
       owner = "hfg-gmuend";
       repo = pname;
       rev = version;
  -    sha256 = "11221xw13lsv2znxs295m61cn69wkp5934b0aaddpki2vp6q3n0r";
  +    sha256 = "0zis0i7fn7dqv39c9ms7f1p4dqqzwdfwkdgrijaak1cmb8rkn3a0";
     };
   
     nativeBuildInputs = [
  -    scfbuild
  +    scfbuildPatched
     ];
   
     # Some id and data-* attributes in the svg files contain unicode characters,
  
positive.code: { stdenv
  , fetchFromGitHub
  , scfbuild
  , variant ? "color" # "color" or "black"
  }:
  
  
negative.code: 
      # Actually build the font:
      cd font
      scfbuild ${scfbuildOptions} -c scfbuild-${variant}.yml
    '';
  
    installPhase = ''
  