anchor.diff:  assert libpngSupport -> libpng != null;
   assert youtubeSupport -> youtube-dl != null;
   assert cacaSupport -> libcaca != null;
  +assert waylandSupport -> (wayland != null && libxkbcommon != null);
   
   let
     inherit (stdenv.lib) optional optionals optionalString;
  
positive.code:     ++ optional youtubeSupport youtube-dl
      ++ optional sdl2Support SDL2
      ++ optional cacaSupport libcaca
      ++ optional vaapiSupport libva;
  
    enableParallelBuilding = true;
  
  
negative.code:     '';
    };
  }
  # TODO: investigate caca support
  # TODO: investigate lua5_sockets bug
  