I'm returning to this thread because a surprising thing happened. I
decided to try to debug the fifo problem I reported at the beginning of
the thread (a hang building TeX Live on Cygwin when the jobserver used a
fifo). So I installed make 4.4.1 built with fifos enabled (by setting
CPPFLAGS=-DJOBSERVER_USE_FIFO=1). And now I can no longer reproduce the
hang.
The only explanation I can think of is that commit 8b8cc3a825, which was
intended to fix a pipe problem, also fixed the fifo problem. Is that
plausible? Or does that commit only affect the behavior of make in the
pipe case?
Ken