anchor.diff:  , cmsSupport         ? true,           lcms2
   , dvdnavSupport      ? stdenv.isLinux, libdvdnav
   , jackaudioSupport   ? false,          libjack2
  +, javascriptSupport  ? true,           mujs
   , libpngSupport      ? true,           libpng
   , openalSupport      ? true,           openalSoft
   , pulseSupport       ? config.pulseaudio or stdenv.isLinux, libpulseaudio
  
positive.code:     (lib.enableFeature archiveSupport  "libarchive")
      (lib.enableFeature cddaSupport     "cdda")
      (lib.enableFeature dvdnavSupport   "dvdnav")
      (lib.enableFeature openalSupport   "openal")
      (lib.enableFeature sdl2Support     "sdl2")
      (lib.enableFeature sixelSupport    "sixel")
  
negative.code:     ++ lib.optionals drmSupport         [ libdrm mesa ]
      ++ lib.optionals dvdnavSupport      [ libdvdnav libdvdnav.libdvdread ]
      ++ lib.optionals jackaudioSupport   [ libjack2 ]
      ++ lib.optionals javascriptSupport  [ mujs ]
      ++ lib.optionals libpngSupport      [ libpng ]
      ++ lib.optionals openalSupport      [ openalSoft ]
      ++ lib.optionals pulseSupport       [ libpulseaudio ]
  