anchor.diff:      buildInputs = [
         irrlicht luajit jsoncpp gettext freetype sqlite curl bzip2 ncurses
         gmp libspatialindex
  -    ] ++ optionals stdenv.isDarwin [ 
  +    ] ++ optionals stdenv.isDarwin [
         libiconv OpenGL OpenAL Carbon Cocoa
       ] ++ optionals buildClient [
         libpng libjpeg libGLU libGL openal libogg libvorbis xorg.libX11 libXxf86vm
  
positive.code:   };
  
    v5 = {
      version = "5.2.0";
      sha256 = "0pj9hkxwc1vzng2khbixi79557sbawf6mqkzl589jciyqa7jqkv1";
      dataSha256 = "1kjz7x3xiqqnpyrd6339a139pbdxx31c4qpg8pmns410hsm8i358";
    };
  
  in {
  
negative.code:     ] ++ optionals buildClient [
        "-DOpenGL_GL_PREFERENCE=GLVND"
      ];
  
      NIX_CFLAGS_COMPILE = "-DluaL_reg=luaL_Reg"; # needed since luajit-2.1.0-beta3
  
      nativeBuildInputs = [ cmake doxygen graphviz ];
  