anchor.diff:  , enableAbsubmit         ? lib.elem stdenv.hostPlatform.system essentia-extractor.meta.platforms, essentia-extractor
   , enableAcousticbrainz   ? true
   , enableAcoustid         ? true
  +, enableAura             ? true
   , enableBadfiles         ? true, flac, mp3val
   , enableBeatport         ? true
   , enableBpsync           ? true
  
positive.code:     pythonPackages.confuse
      pythonPackages.mediafile
      gobject-introspection
    ] ++ lib.optional enableAbsubmit      essentia-extractor
      ++ lib.optional enableAcoustid      pythonPackages.pyacoustid
      ++ lib.optional enableBeatport      pythonPackages.requests_oauthlib
      ++ lib.optional (enableFetchart
                || enableDeezer
                || enableEmbyupdate
                || enableKodiupdate
                || enableLoadext
                || enablePlaylist
                || enableSubsonicplaylist
                || enableSubsonicupdate
                || enableAcousticbrainz)
                                      pythonPackages.requests
      ++ lib.optional enableCheck         beetsExternalPlugins.check
      ++ lib.optional enableConvert       ffmpeg
      ++ lib.optional enableDiscogs       pythonPackages.discogs_client
      ++ lib.optional enableKeyfinder     keyfinder-cli
      ++ lib.optional enableLastfm        pythonPackages.pylast
      ++ lib.optional enableMpd           pythonPackages.mpd2
      ++ lib.optional enableSonosUpdate   pythonPackages.soco
      ++ lib.optional enableThumbnails    pythonPackages.pyxdg
      ++ lib.optional enableWeb           pythonPackages.flask
      ++ lib.optional enableAlternatives  beetsExternalPlugins.alternatives
      ++ lib.optional enableCopyArtifacts beetsExternalPlugins.copyartifacts
      ++ lib.optional enableExtraFiles    beetsExternalPlugins.extrafiles
    ;
  
    buildInputs = [
  
negative.code:   optionalPlugins = {
      absubmit = enableAbsubmit;
      acousticbrainz = enableAcousticbrainz;
      aura = enableAura;
      badfiles = enableBadfiles;
      beatport = enableBeatport;
      bpsync = enableBpsync;
  