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Unable to pickle abstract class (using abc.ABC) with type annotations #572
Description
Starting with Python 3.14a3, the following raises a TypeError:
from abc import ABC
import cloudpickle
def class_factory():
class Model(ABC):
field: int
return Model
cloudpickle.dumps(class_factory())
"""
TypeError: cannot pickle '_abc._abc_data' object
when serializing dict item '_abc_impl'
when serializing tuple item 0
when serializing cell reconstructor arguments
when serializing cell object
when serializing tuple item 0
when serializing dict item '__closure__'
when serializing tuple item 1
when serializing function state
when serializing function object
when serializing dict item '__annotate_func__'
when serializing tuple item 0
when serializing abc.ABCMeta state
when serializing abc.ABCMeta object
"""Reacted by Olivier Grisel and Guillaume Lemaitre
Reacted by Copilot
Activity
ogrisel commentedon Oct 31, 2025
@Viicos thanks for the report. Would you be interested in investigating whether it's possible to add support for this?
Viicos commentedon Oct 31, 2025
I reported the issue as I encountered it when adding support for Python 3.14 in Pydantic, and got tests failing. I won't have capacity to look into this.
ogrisel commentedon Oct 31, 2025
I opened a mirror issue on CPython since this code used to work with CPython 3.13 and the resulting change of picklability status might not have been intended.
glemaitre commentedon Oct 31, 2025
I'll give a shot at it and see where it goes.
ogrisel commentedon Oct 31, 2025
Let me try to assign this to copilot to check its capabilities on a real life problem.