anchor.diff:    libGL, spice-protocol, zlib, libGLU, dbus, libunwind, libdrm,
     mesa, udev, bootstrap_cmds, bison, flex, clangStdenv, autoreconfHook,
     mcpp, libepoxy, openssl, pkg-config, llvm, libxslt, libxcrypt,
  -  ApplicationServices, Carbon, Cocoa, Xplugin
  +  ApplicationServices, Carbon, Cocoa, Xplugin,
  +  xorg
   }:
   
   let
  
positive.code:     outputs = [ "out" "dev" "doc" ];
      configureFlags = attrs.configureFlags or []
        ++ malloc0ReturnsNullCrossFlag;
      buildInputs = attrs.buildInputs ++ [self.xorgproto];
    });
  
    libXp = super.libXp.overrideAttrs (attrs: {
  
negative.code:       rev = "31486f40f8e8f8923ca0799aea84b58799754564";
        sha256 = "sha256-nqT9VZDb2kAC72ot9UCdwEkM1uuP9NriJePulzrdZlM=";
      };
      buildInputs = attrs.buildInputs ++ [ xorg.libXScrnSaver xorg.libXfixes xorg.libXv xorg.pixman xorg.utilmacros ];
      nativeBuildInputs = attrs.nativeBuildInputs ++ [autoreconfHook ];
      configureFlags = [ "--with-default-dri=3" "--enable-tools" ];
  
  