AttributeError: Can't pickle local object when Running with Python 3.8 about pytest-parallel HOT 6 CLOSED

Ping?

from pytest-parallel.

Related https://bugs.python.org/issue33884

from pytest-parallel.

Confirm the issue also with pytest-parallel==0.0.10 but exclusively on Darwin. It is still safe on linux-based OS

from pytest-parallel.

I have the same problem on this platform:
platform darwin -- Python 3.8.1, pytest-5.3.5, py-1.8.1, pluggy-0.13.1

from pytest-parallel.

From https://docs.python.org/3/library/multiprocessing.html:

Changed in version 3.8: On macOS, the spawn start method is now the default. The fork start method should be considered unsafe as it can lead to crashes of the subprocess. See bpo-33725.

So you could set it manually to "forkserver" I guess.

import multiprocessing as mp; mp.set_start_method("forkserver")

Apart from that pytest-xdist might be a good alternative for executing tests in parallel.

from pytest-parallel.

I force fork on macOS in 0.1.0, which fixes the problem. This sacrifices safety to keep usability, so I've added a notice to the README.

from pytest-parallel.