I just tested and this Makefile works fine with clang, except that -flto should be added to LDFLAGS. In fact I believe it should be there for gcc too, accordin

I just tested and this Makefile works fine with clang, except that -flto should be added to LDFLAGS. In fact I believe it should be there for gcc too, according to https://gcc.gnu.org/wiki/LinkTimeOptimization https://gcc.gnu.org/wiki/LinkTimeOptimization so perhaps this is a bug in the Makefile? Flushing out issues like this is another reason to commit to writing portable code (and build systems), as you put it.