Hello. In some cases, make --shuffle option (available in GNU make 4.4) "amplifies" the probability that a Makefile bug shows up. I suggest that you people give it a try. There is a blog entry from the author explaining --shuffle option: https://trofi.github.io/posts/238-new-make-shuffle-mode.html [ I'm just a long-time lurker in this list, but maybe this could help ] Thanks.