Sphinx build hangs when a BaseException occurs #25161
Description
Python's multiprocessing.Pool hangs when a BaseException that is not an Excepion happens in the function it runs; we need to wrap these in "normal" Exception's so they get thrown correctly by the pool's get.
Here's a minimal Python session to showcase this problem:
Python 2.7.14 (default, Jan 5 2018, 10:41:29)
[GCC 7.2.1 20171224] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> def work(x):
... raise BaseException(x)
...
>>> from multiprocessing import Pool
>>> pool = Pool(2)
>>> pool.map_async(work, ["error", "error"]).get()
Process PoolWorker-1:
Process PoolWorker-2:
Traceback (most recent call last):
Traceback (most recent call last):
File "/usr/lib/python2.7/multiprocessing/process.py", line 267, in _bootstrap
File "/usr/lib/python2.7/multiprocessing/process.py", line 267, in _bootstrap
self.run()
File "/usr/lib/python2.7/multiprocessing/process.py", line 114, in run
self.run()
File "/usr/lib/python2.7/multiprocessing/process.py", line 114, in run
self._target(*self._args, **self._kwargs)
self._target(*self._args, **self._kwargs)
File "/usr/lib/python2.7/multiprocessing/pool.py", line 113, in worker
File "/usr/lib/python2.7/multiprocessing/pool.py", line 113, in worker
result = (True, func(*args, **kwds))
File "/usr/lib/python2.7/multiprocessing/pool.py", line 65, in mapstar
result = (True, func(*args, **kwds))
return map(*args)
File "/usr/lib/python2.7/multiprocessing/pool.py", line 65, in mapstar
File "<stdin>", line 2, in work
return map(*args)
File "<stdin>", line 2, in work
BaseException: error
BaseException: error
[hangs]
This upstreams part of Debian's u2-better-sphinx-failure-modes.patch.
CC: @infinity0
Component: doctest framework
Author: Julian Rüth
Branch/Commit: 319849a
Reviewer: Erik Bray
Issue created by migration from https://trac.sagemath.org/ticket/25161