anchor.diff:      discogs = enableDiscogs;
       embyupdate = enableEmbyupdate;
       fetchart = enableFetchart;
  +    gmusic = enableGmusic;
       keyfinder = enableKeyfinder;
  +    kodiupdate = enableKodiupdate;
       lastgenre = enableLastfm;
       lastimport = enableLastfm;
       mpdstats = enableMpd;
  
positive.code: 
  in pythonPackages.buildPythonApplication rec {
    name = "beets-${version}";
    version = "1.4.3";
  
    src = fetchFromGitHub {
      owner = "beetbox";
      repo = "beets";
      rev = "v${version}";
      sha256 = "0sh2ap7jbqh7p8h63kgrx1ja9lyqlxjpfnh6axxw9p1mh78cgc1v";
    };
  
    propagatedBuildInputs = [
  
negative.code:   ] ++ optional enableAcoustid     pythonPackages.pyacoustid
      ++ optional (enableFetchart
                || enableEmbyupdate
                || enableKodiupdate
                || enableAcousticbrainz)
                                     pythonPackages.requests
      ++ optional enableConvert      ffmpeg
      ++ optional enableDiscogs      pythonPackages.discogs_client
      ++ optional enableGmusic       pythonPackages.gmusicapi
      ++ optional enableKeyfinder    keyfinder-cli
      ++ optional enableLastfm       pythonPackages.pylast
      ++ optional enableMpd          pythonPackages.mpd2
      ++ optional enableThumbnails   pythonPackages.pyxdg
      ++ optional enableWeb          pythonPackages.flask
      ++ optional enableAlternatives (import ./alternatives-plugin.nix {
  