python: More build fixes.
diff --git a/src/gallium/SConscript b/src/gallium/SConscript
index ba541f9..c833d83 100644
--- a/src/gallium/SConscript
+++ b/src/gallium/SConscript
@@ -7,6 +7,9 @@
 for driver in env['drivers']:
 	SConscript(os.path.join('drivers', driver, 'SConscript'))
 
+# Needed by some state trackers
+SConscript('winsys/null/SConscript')
+
 SConscript('state_trackers/python/SConscript')
 if platform != 'embedded':
 	SConscript('state_trackers/glx/xlib/SConscript')