Bug report

Bug description:

With #111815, any exception raised inside the __init__ method of an enum class ¹ is expected to be:

1. instantiable (not the case with Pydantic ValidationErrors, see Python 3.12 Enum Class Validated Initialization TypeError pydantic/pydantic#10593)
2. instantiable and expected to take a single argument.

Meaning the following raises a TypeError instead of the expected MyValueError:

class MyValueError(ValueError):
    def __init__(self, t: str, v: int) -> None:
        self.t = t
        self.v = v

class ValidatedEnum(Enum):
    def __init__(self, value):
        raise MyValueError("", 1)


class MyValidatedEnum(ValidatedEnum):
    FOO = "foo"

# TypeError: MyValueError.__init__() missing 1 required positional argument: 'v'

CPython versions tested on:

3.12

Operating systems tested on:

Linux

Linked PRs

• gh-125259: Fix error notes removal in enum initialization #125647
• [3.13] gh-125259: Fix error notes removal in enum initialization (GH-125647) #125858
• [3.12] gh-125259: Fix error notes removal in enum initialization (GH-125647) #125953