Re: Regression on Cygwin: Problems with parallel make in 4.4

[Paul Smith]

On Wed, 2023-02-15 at 13:57 -0500, Ken Brown wrote:
> One thing to keep in mind here is that your tests on Cygwin were done
> on Cygwin 2.9.0, in which FIFOs were very poorly supported.  For
> example, a FIFO couldn't have multiple readers or writers.  If
> GNU/Hurd has similar limitations, that could explain the similar test
> results.
> 
> Cygwin's FIFO implementation was completely rewritten starting with
> 3.0, and it now supports multiple readers and writers.  So the issue
> with current Cygwin is more likely a bug in Cygwin and/or make.

GNU make _definitely_ has multiple readers/writers (that's really the
whole point :)).

So I'm not sure where to go from here on Cygwin.  Should I force Cygwin
builds to use the "pipe" jobserver, as I've done for GNU/Hurd?  Should
I add preprocessor checks (or autoconf checks?) to try to figure out
which version of Cygwin is being used and choose based on that?  I
don't know how to check versions.