anchor.diff:  
   in pythonPackages.buildPythonApplication rec {
     name = "beets-${version}";
  -  version = "1.4.3";
  +  version = "1.4.5";
   
     src = fetchFromGitHub {
       owner = "beetbox";
       repo = "beets";
       rev = "v${version}";
  -    sha256 = "0sh2ap7jbqh7p8h63kgrx1ja9lyqlxjpfnh6axxw9p1mh78cgc1v";
  +    sha256 = "0fvfp9ckq3dhs4f8abg9fprfppyf0g6mv8br2xz99plg4wnffzmy";
     };
   
     propagatedBuildInputs = [
  
positive.code:       s,"mp3val","${mp3val}/bin/mp3val",
      }' beetsplug/badfiles.py
    '' + optionalString enableConvert ''
      sed -i -e 's,\(util\.command_output(\)\([^)]\+\)),\1[b"${ffmpeg.bin}/bin/ffmpeg" if args[0] == b"ffmpeg" else args[0]] + \2[1:]),' beetsplug/convert.py 
    '' + optionalString enableReplaygain ''
      sed -i -re '
        s!^( *cmd *= *b?['\'''"])(bs1770gain['\'''"])!\1${bs1770gain}/bin/\2!
  
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 {
  