anchor.diff:  { stdenv, fetchurl, substituteAll
   , libXrender, libXinerama, libXcursor, libXmu , libXv, libXext
   , libXfixes, libXrandr, libSM, freetype, fontconfig
  -, zlib, libjpeg, libpng, libmng, which, mesa, mesa_glu, openssl, dbus, cups, pkgconfig
  +, zlib, libjpeg, libpng, libmng, which, mesaSupported, mesa, mesa_glu, openssl, dbus, cups, pkgconfig
   , libtiff, glib, icu
   , mysql, postgresql, sqlite
   , perl, coreutils, libXi
  
positive.code:     [ libXrender libXrandr libXinerama libXcursor libXext libXfixes libXv libXi
        libSM zlib libpng openssl dbus.libs freetype fontconfig glib ]
          # Qt doesn't directly need GLU (just GL), but many apps use, it's small and doesn't remain a runtime-dep if not used
      ++ optional (stdenv.lib.lists.elem stdenv.system stdenv.lib.platforms.mesaPlatforms) mesa_glu
      ++ optional ((buildWebkit || buildMultimedia) && stdenv.isLinux ) alsaLib
      ++ optionals (buildWebkit || buildMultimedia) [ gstreamer gst_plugins_base ];
  
  
negative.code:         src = ./dlopen-absolute-paths.diff;
          inherit cups icu libXfixes;
          glibc = stdenv.gcc.libc;
          openglDriver = if mesaSupported then mesa.driverLink else "/no-such-path";
        })
      ] ++ stdenv.lib.optional gtkStyle (substituteAll {
          src = ./dlopen-gtkstyle.diff;
  