Hi, http://llvm.org/docs/MakefileGuide.html says Override Variables =============Override variables can be used to override the default values provided by the LLVM makefile system. These variables can be set in several ways: In the environment (e.g. setenv, export) -- not recommended. On the make command line -- recommended. On the configure command line In the Makefile (only *after* the inclusion of $(LEVEL)/Makefile.common). Should that *after* be *before*? *before* seems to be working for me. Jianzhou