File "/tmp/.tox/py312-linux-pyqt5-no_cov/lib/python3.12/site-packages/pydantic_compat/_v2/mixin.py", line 58, in <module>
class PydanticCompatMixin(metaclass=_MixinMeta):
File "/tmp/.tox/py312-linux-pyqt5-no_cov/lib/python3.12/site-packages/pydantic_compat/_v2/mixin.py", line 55, in __new__
return super().__new__(cls, name, bases, namespace, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/tmp/.tox/py312-linux-pyqt5-no_cov/lib/python3.12/site-packages/pydantic/_internal/_model_construction.py", line 246, in __new__
del namespace[instance_slot]
~~~~~~~~~^^^^^^^^^^^^^^^
KeyError: '__pydantic_fields_set__'
See napari's CI, output:
It looks like this was caused by #10110, here:
pydantic/pydantic/_internal/_model_construction.py
Lines 245 to 246 in 714c0df