dataclasses fail to unpickle when there is an object cycle with a custom __hash__ function

[charles-cooper]

extracting the dataclasses issue mentioned in #124937 (comment) into its own issue

Linked PRs

• gh-125004: fix unpickling for dataclasses in a cycle via hashing #125005

[gpshead]

Could you also look into how the attrs library handles this situation or not? (and file an issue there if not)

[charles-cooper]

Could you also look into how the attrs library handles this situation or not? (and file an issue there if not)

I did a quick search through the codebase and found this python-attrs/attrs#613, which seems vaguely related but likely not the same issue. I'm not sure I have time to reproduce+triage the issue in attrs but maybe I can make a stub issue?