Re: master 8dcb19f 4/4: Add a unit test testing interaction between threads and processes.

[Eli Zaretskii <eliz@gnu.org>]

> From: Philipp Stephani <p.stephani2@gmail.com>
> Date: Sat, 23 Jan 2021 21:34:28 +0100
> Cc: Emacs developers <emacs-devel@gnu.org>, Philipp Stephani <phst@google.com>
> > I did verify that process-send-eof does cause 'cat' to exit, so the
> > problem is likely in some issue related to threads and what the test
> > assumes regarding what should happen here.
> 
> What's surprising here is that "cat" exited with an exit status of 1,
> shouldn't that be normally impossible?

I'm not sure this 1 exit status is not a red herring: when I manually
perform the steps for a single process and without any threads, 'cat'
exits with status zero.  And when I run that single test, it hangs.
So I think the exit code of 1 reaped by some thread is just some side
effect of running previous tests in process-tests.el.