diff -r 77591ef8983a -r 3d7ea1dbe0de make/linux/makefiles/buildtree.make
--- a/make/linux/makefiles/buildtree.make	Mon Mar 19 20:13:17 2012 +0100
+++ b/make/linux/makefiles/buildtree.make	Mon Mar 19 10:09:24 2012 +0100
@@ -66,7 +66,7 @@
 # For now, until the compiler is less wobbly:
 TESTFLAGS	= -Xbatch -showversion
 
-ifeq ($(ZERO_BUILD), true)
+ifeq ($(findstring true, $(JVM_VARIANT_ZERO) $(JVM_VARIANT_ZEROSHARK)), true)
   PLATFORM_FILE = $(shell dirname $(shell dirname $(shell pwd)))/platform_zero
 else
   ifdef USE_SUNCC