Sighhhh. I believe I have the answer: Pulling a Galois on my situation: There is no solution in Cygwin under Windows-7. :-((

How did I come to this conclusion? I had installed the Guardian browser so my daughter could take an online exam. It barfed at its startup with an almost identical error. The instructor told her she needs to do it on at least Windows-10. I am redoing the project on my Windows-11 PC and the make works just fine.

Yeah, I suppose I could download the source code for make and compile it on my Windows-7 Cygwin but it's time to acknowledge that times has passed me by on that OS. Nostalgia, as the Borg might say, is irrelevant. And persistence is futile. (I don't think they ever said that!)