anchor.diff:  with stdenv.lib;
   
   let
  -  emojiSrcs = {
  -    data = fetchurl {
  -      url = "http://unicode.org/Public/emoji/5.0/emoji-data.txt";
  -      sha256 = "11jfz5rrvyc2ixliqfcjgmch4cn9mfy0x96qnpfcyz5fy1jvfyxf";
  -    };
  -    sequences = fetchurl {
  -      url = "http://unicode.org/Public/emoji/5.0/emoji-sequences.txt";
  -      sha256 = "09bii7f5mmladg0kl3n80fa9qaix6bv5ylm92x52j7wygzv0szb1";
  -    };
  -    variation-sequences = fetchurl {
  -      url = "http://unicode.org/Public/emoji/5.0/emoji-variation-sequences.txt";
  -      sha256 = "1wlg4gbq7spmpppjfy5zdl82sj0hc836p8gljgfrjmwsjgybq286";
  -    };
  -    zwj-sequences = fetchurl {
  -      url = "http://unicode.org/Public/emoji/5.0/emoji-zwj-sequences.txt";
  -      sha256 = "16gvzv76mjv9g81lm1m6cr3rpfqyn2k4hb9a62xd329252dhl25q";
  -    };
  -    test = fetchurl {
  -      url = "http://unicode.org/Public/emoji/5.0/emoji-test.txt";
  -      sha256 = "031qk2v8xdnba7hfinmgrmpglc9l8ll2hds6mw885p0hngdb3dgw";
  -    };
  -  };
  -  emojiData = stdenv.mkDerivation {
  -    name = "emoji-data-5.0";
  -    dontUnpack = true;
  -    installPhase = ''
  -      mkdir $out
  -      ${builtins.toString (flip mapAttrsToList emojiSrcs (k: v: "cp ${v} $out/emoji-${k}.txt;"))}
  -    '';
  -  };
  -  cldrEmojiAnnotation = stdenv.mkDerivation rec {
  -    pname = "cldr-emoji-annotation";
  -    version = "31.90.0_1";
  -    src = fetchFromGitHub {
  -      owner = "fujiwarat";
  -      repo = "cldr-emoji-annotation";
  -      rev = version;
  -      sha256 = "1vsj32bg8ab4d80rz0fxy6sj2lv31inzyjnddjm079bnvlaf2kih";
  -    };
  -    nativeBuildInputs = [ autoreconfHook ];
  -  };
  -  ucdVersion = "12.0.0";
  -  ucdSrcs = {
  -    NamesList = fetchurl {
  -      url = "https://www.unicode.org/Public/${ucdVersion}/ucd/NamesList.txt";
  -      sha256 = "c17c7726f562bd9ef869096807f0297e1edef9a58fdae1fbae487378fa43586f";
  -    };
  -    Blocks = fetchurl {
  -      url = "https://www.unicode.org/Public/${ucdVersion}/ucd/Blocks.txt";
  -      sha256 = "a1a3ca4381eb91f7b65afe7cb7df615cdcf67993fef4b486585f66b349993a10";
  -    };
  -  };
  -  ucd = stdenv.mkDerivation {
  -    name = "ucd-${ucdVersion}";
  -    dontUnpack = true;
  -    installPhase = ''
  -      mkdir $out
  -      ${builtins.toString (flip mapAttrsToList ucdSrcs (k: v: "cp ${v} $out/${k}.txt;"))}
  -    '';
  -  };
     python3Runtime = python3.withPackages (ps: with ps; [ pygobject3 ]);
     python3BuildEnv = python3.buildEnv.override {
       # ImportError: No module named site
  
positive.code: , gtk3
  , gtk-doc
  , isocodes
  , python3
  , json-glib
  , libnotify ? null
  
negative.code:     (enableFeature enablePython2Library "python-library")
      (enableFeature enablePython2Library "python2") # XXX: python2 library does not work anyway
      (enableFeature enableUI "ui")
      "--with-unicode-emoji-dir=${unicode-emoji}/share/unicode/emoji"
      "--with-emoji-annotation-dir=${cldr-emoji-annotation}/share/unicode/cldr/common/annotations"
      "--with-ucd-dir=${unicode-character-database}/share/unicode"
    ];
  
    nativeBuildInputs = [
  