xwd was not able to compile on ubuntu 12.04

without it, it finishes with many errors like :
undefined reference to `XDestroyRegion'

component/xorg/buildout.cfg

@@ -481,6 +481,7 @@ environment =
   PKG_CONFIG_PATH=${xorg-util-macros:location}/share/pkgconfig:${xproto:location}/lib/pkgconfig:${libX11:location}/lib/pkgconfig:${libxkbfile:location}/lib/pkgconfig
   CPPFLAGS=-I${xproto:location}/include -I${libX11:location}/include -I${libxkbfile:location}/include# -I${xfixes:location}/include -I${libXrender:location}/include
   LDFLAGS=-L${xproto:location}/lib -Wl,-rpath=${xproto:location}/lib -L${libX11:location}/lib -Wl,-rpath=${libX11:location}/lib -L${libxkbfile:location}/lib -Wl,-rpath=${libxkbfile:location}/lib -lX11
+  XWD_LIBS=-lX11
 
 [xserver]
 # Adds Xvfb functionnality