I don’t mind sticking to bash, but some of the other choices seem overly opinionated. In my experience the best Makefiles just invoke other commands, so you’re only using make for its dependency tracking. That way the Makefile remains fairly simple and you can use something more sensible (bash instead of bash-in-make, python, whatever) to write your actual build logic.

The Makefile should probably be listed as a dependency for all the rules too, otherwise you’re gonna end up dealing with stale results and adding a “clean” target.