It would be helpful to know what version you are actually using, as the expansion of pathnames has at least been rewritten 3 times during the last 9 months.
Since you're talking about makefiles, however, it is probably a bug. If you are using RC2, it is a bug in RC2, and if you are using a recent build, it is a bug in your self-made makefile (since export to makefile no longer exists).