If one executes "make clean" in subdirectories to Examples projects, e.g. Examples/simple/tests, it is possible that OBJ_EXT is not set and "make clean" will "rm *" instead of "rm *.o". "git checkout" can restore the deleted files but not any changes extant before the "make clean".
Mike, I found and fixed the problem. If you want to pull from https://github.com/ebo/pFUnit.git
As a note, the problem is that the Example/*/tests/GNUMakefile does not contain the OBJ_EXT definition. I was able to resolve that by including $(PFUNIT)/include/base.mk.