[issue35537] use os.posix_spawn in subprocess

[STINNER Victor]

STINNER Victor <vstinner at redhat.com> added the comment:

> I am going to merge the PR tomorrow, except if someone sees a good reason to not merge it.

I changed my mind and I decided to wait until I'm back from holiday instead :-)
https://github.com/python/cpython/pull/11242#issuecomment-449151524

The function is more tricky than what I expected!

----------

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue35537>
_______________________________________