diff -r 633f2378c904 -r c8d320b48626 common/makefiles/MakeBase.gmk
--- a/common/makefiles/MakeBase.gmk	Mon Jun 25 21:37:09 2012 -0700
+++ b/common/makefiles/MakeBase.gmk	Tue Jul 03 16:11:12 2012 -0700
@@ -138,6 +138,7 @@
 
 # Hook to be called as the very first thing when running a normal build
 define AtRootMakeStart
+	$(if $(findstring -j,$(MAKEFLAGS)), $(error make -j is not supported, use make JOBS=n))
 	$(call PrintStartMessage)
 	$(call StartTimer)
 endef