--- old/common/autoconf/spec.gmk.in	2015-03-06 17:10:55.012071262 +0100
+++ new/common/autoconf/spec.gmk.in	2015-03-06 17:10:54.900071264 +0100
@@ -324,6 +324,7 @@
 C_FLAG_DEPS:=@C_FLAG_DEPS@
 CXX_FLAG_DEPS:=@CXX_FLAG_DEPS@
 
+DISABLE_WARNING_PREFIX := @DISABLE_WARNING_PREFIX@
 CFLAGS_WARNINGS_ARE_ERRORS:=@CFLAGS_WARNINGS_ARE_ERRORS@
 
 CFLAGS_CCACHE:=@CFLAGS_CCACHE@