anchor.diff:      ++ optional (enableFetchart
                 || enableEmbyupdate
                 || enableKodiupdate
  +              || enableLoadext
  +              || enablePlaylist
  +              || enableSubsonicupdate
                 || enableAcousticbrainz)
                                       pythonPackages.requests
       ++ optional enableConvert       ffmpeg
  
positive.code: 
  in pythonPackages.buildPythonApplication rec {
    pname = "beets";
    version = "1.4.7";
  
    src = fetchFromGitHub {
      owner = "beetbox";
      repo = "beets";
      rev = "v${version}";
      sha256 = "17gfz0g7pqm6wha8zf63zpw07zgi787w1bjwdcxdh1l3z4m7jc9l";
    };
  
    propagatedBuildInputs = [
  
negative.code:   patches = [
      ./replaygain-default-bs1770gain.patch
      ./keyfinder-default-bin.patch
    ];
  
    postPatch = ''
  