I've recently been lightly toasted by GNU Make's implicit "old-fashioned" suffix rules, where it was looking for YACC files as prerequisites for my own generated C code. The manual suggests a workaround that clears the implicit suffixes and also allows you to add back the ones you want. For me, clearing all of them with an empty ".SUFFIXES :" rule was exactly what I needed.

https://www.gnu.org/software/make/manual/html_node/Suffix-Ru...