--- a/jdk/make/common/shared/Defs-linux.gmk	Mon Nov 29 10:37:44 2010 -0800
+++ b/jdk/make/common/shared/Defs-linux.gmk	Tue Nov 30 13:53:06 2010 -0800
@@ -123,7 +123,7 @@
 
 # GCC29_COMPILER_PATH: is the path to where the gcc 2.9 compiler is installed
 #  NOTE: Must end with / so that it could be empty, allowing PATH usage.
-ifdef ALT_GCC29_COMPILER_PATH
+ifneq "$(origin ALT_GCC29_COMPILER_PATH)" "undefined"
   GCC29_COMPILER_PATH :=$(call PrefixPath,$(ALT_GCC29_COMPILER_PATH))
 else
   GCC29_COMPILER_PATH = $(JDK_DEVTOOLS_DIR)/$(PLATFORM)/gcc29/usr/