python / python/cpython

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

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#125,004 2 comments 0 reactions 0 assignees View on GitHub

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topic-dataclasses type-bug
Dominant language
Python
Stars
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Forks
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PR merge metrics
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Description

extracting the dataclasses issue mentioned in https://github.com/python/cpython/issues/124937#issuecomment-2395064821 into its own issue

Linked PRs
  • gh-125005

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reading the originating dataclasses discussion in issue 124937 and the linked PR gh-125005. Reproduce the object-cycle case with a custom hash function, then verify that the dataclass can be unpickled successfully.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
backend
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
15/100

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