pytest-dev / pytest-dev/pytest-xdist

xdist does not work with --assert=plain

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#293 4 comments 2 reactions 0 assignees View on GitHub

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bug
Dominant language
Python
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Description

Running
pytest --doctest-modules -v --assert=plain
works without assert rewriting.

Running
pytest --doctest-modules -v --assert=plain -n 2
is still doing the assert rewriting.

I have to use --assert=plain as the tests are using pickle and assert rewriting is creating problems with pickle. Specifically it tries to pickle typing.io which does not support pickling.

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Research direction

Reproduce the two commands in the issue, comparing pytest --assert=plain with and without -n 2. Trace how pytest-xdist starts workers and applies assertion rewriting; done means --assert=plain is honored in distributed runs and the pickle-related rewriting problem no longer occurs.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
testing-qa
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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