anchor.diff:  , gobjectSupport ? true, glib
   , stdenv, fetchurl, pkgconfig, x11, fontconfig, freetype, xlibs
   , zlib, libpng, pixman, libxcb ? null, xcbutil ? null
  +, gettext
   }:
   
   assert postscriptSupport -> zlib != null;
  
positive.code:     homepage = http://cairographics.org/;
  
      licenses = [ "LGPLv2+" "MPLv1" ];
    };
  }
  
negative.code:   buildInputs =
      [ pkgconfig x11 fontconfig pixman xlibs.libXrender ]
      ++ stdenv.lib.optionals xcbSupport [ libxcb xcbutil ]
      ++ stdenv.lib.optional gobjectSupport glib
  
      # On non-GNU systems we need GNU Gettext for libintl.
      ++ stdenv.lib.optional (!stdenv.isLinux) gettext;
  
    propagatedBuildInputs =
      [ freetype ] ++
  