anchor.diff:  assert pulseSupport       -> available libpulseaudio;
   assert rubberbandSupport  -> available rubberband;
   assert screenSaverSupport -> available libXScrnSaver;
  -assert sambaSupport       -> available samba;
   assert sdl2Support        -> available SDL2;
  -assert sndioSupport       -> available sndio;
   assert speexSupport       -> available speex;
   assert theoraSupport      -> available libtheora;
   assert vaapiSupport       -> available libva;
  
positive.code: 
  in stdenv.mkDerivation rec {
    pname = "mpv";
    version = "0.32.0";
  
    src = fetchFromGitHub {
      owner  = "mpv-player";
      repo   = "mpv";
      rev    = "v${version}";
      sha256 = "0kmy1q0hp87vq4rpv7py04x8bpg1wmlzaibavmkf713jqp6qy596";
    };
  
    postPatch = ''
  
negative.code: , libpngSupport      ? true,           libpng        ? null
  , pulseSupport       ? config.pulseaudio or stdenv.isLinux, libpulseaudio ? null
  , rubberbandSupport  ? stdenv.isLinux, rubberband    ? null
  , screenSaverSupport ? true,           libXScrnSaver ? null
  , sdl2Support        ? true,           SDL2          ? null
  , speexSupport       ? true,           speex         ? null
  , swiftSupport       ? false,          swift         ? null
  , theoraSupport      ? true,           libtheora     ? null
  