anchor.diff:    , mesa   ? null
   
   , alsaSupport        ? stdenv.isLinux, alsaLib       ? null
  +, archiveSupport     ? true,           libarchive    ? null
   , bluraySupport      ? true,           libbluray     ? null
   , bs2bSupport        ? true,           libbs2b       ? null
   , cacaSupport        ? true,           libcaca       ? null
   , cmsSupport         ? true,           lcms2         ? null
   , dvdnavSupport      ? stdenv.isLinux, libdvdnav     ? null
  +, jackaudioSupport   ? false,          libjack2      ? null
   , libpngSupport      ? true,           libpng        ? null
  +, openalSupport      ? true,           openalSoft    ? null
   , pulseSupport       ? config.pulseaudio or stdenv.isLinux, libpulseaudio ? null
   , rubberbandSupport  ? stdenv.isLinux, rubberband    ? null
   , screenSaverSupport ? true,           libXScrnSaver ? null
   , sdl2Support        ? true,           SDL2          ? null
  +, sixelSupport       ? false,          libsixel      ? null
   , speexSupport       ? true,           speex         ? null
   , swiftSupport       ? false,          swift         ? null
   , theoraSupport      ? true,           libtheora     ? null
   , vaapiSupport       ? stdenv.isLinux, libva         ? null
  +, vapoursynthSupport ? false,          vapoursynth   ? null
   , vdpauSupport       ? true,           libvdpau      ? null
   , xineramaSupport    ? stdenv.isLinux, libXinerama   ? null
   , xvSupport          ? stdenv.isLinux, libXv         ? null
   , zimgSupport        ? true,           zimg          ? null
  -, archiveSupport     ? true,           libarchive    ? null
  -, jackaudioSupport   ? false,          libjack2      ? null
  -, openalSupport      ? true,           openalSoft    ? null
  -, vapoursynthSupport ? false,          vapoursynth   ? null
   }:
   
   with stdenv.lib;
  
positive.code:     ++ optional rubberbandSupport  rubberband
      ++ optional screenSaverSupport libXScrnSaver
      ++ optional sdl2Support        SDL2
      ++ optional speexSupport       speex
      ++ optional theoraSupport      libtheora
      ++ optional vaapiSupport       libva
  
negative.code:     (enableFeature dvdnavSupport   "dvdnav")
      (enableFeature openalSupport   "openal")
      (enableFeature sdl2Support     "sdl2")
      (enableFeature sixelSupport    "sixel")
      (enableFeature vaapiSupport    "vaapi")
      (enableFeature waylandSupport  "wayland")
      (enableFeature stdenv.isLinux  "dvbin")
  