[3.7] bpo-22087: Fix Policy.get_event_loop() to detect fork (GH-7208)

[miss-islington]

Original patch by Dan O'Reilly.
(cherry picked from commit 5d97b7b)

Co-authored-by: Yury Selivanov yury@magic.io

https://bugs.python.org/issue22087

[vstinner]

IHMO it's too late for 3.7.

[bedevere-bot]

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[vstinner]

https://bugs.python.org/issue22087 is as old as asyncio and people learnt how to work around the issue. I don't think that there is any kind of urgency to merge this change into 3.7. I would prefer to leave 3.7 unchanged, and test the change in 3.8 instead. It's too late for 3.7, we are very close to the 3.7rc1.

[1st1]

I don't see why it's too late.

is as old as asyncio and people learnt how to work around the issue

This doesn't sound as an actual explanation why this shouldn't be merged. I don't see any technical problem with this patch or how it can possibly break anything.

[miss-islington]

@1st1: Backport status check is done, and it's a success ✅ .

[miss-islington]

Thanks!