Tool for debugging makefiles

Question

I have a large legacy codebase with very complicated makefiles, with lots of variables. Sometimes I need to change them, and I find that it's very difficult to figure out why the change isn't working the way I expect. What I'd like to find is a tool that basically does step-through-debugging of the "make" process, where I would give it a directory, and I would be able to see the value of different variables at different points in the process. None of the debug flags to make seem to show me what I want, although it's possible that I'm missing something. Does anyone know of a way to do this?

Answer 1

Have you been looking at the output from running make -n and make -np, and the biggie make -nd?

Are you using a fairly recent version of gmake?

Have you looked at the free chapter on Debugging Makefiles available on O'Reilly's site for their excellent book "Managing Projects with GNU Make" (Amazon Link).