I'm on OS X 10.5.7 Intel and when I enable universal atomic parsley does not build. The makefile seems to have several errors:
1. These required lines are missing:
2. DARWIN_CROSS_ARCH is incorrectly set to i365, it should be (no spaces is very important):
3. I'm not 100% sure on this one since I added the changes to the makefile before doing the other two, but anyway I put on all g++ lines in the Makefile this option following the existing -arch $(DARWIN_CROSS_ARCH) and -arch $(DARWIN_NATIVE_ARCH) bits:
With all 3 of those changes, as I said I'm not sure if the last one is needed, I got a successful universal build on OS X 10.5.