Autoreloader crashes on re-raising exceptions with custom signature.

[Alan Trick]

How to reproduce:

In apps.py, put the following code, and update init.py or the settings to have this app config be used.

from django.apps import AppConfig

class MyException(Exception):
    def __init__(self, value: str, other_thing: str):
        super().__init__(value)
        self.ot = other_thing

class Config(AppConfig):
    name = "myapp"
    verbose_name = "My App"

    def ready(self):
        raise MyException("foo", "bar")

The problem is that django.utils.autoreload.raise_last_exception tries to construct a new exception of the same type, with 1 argument (the original exception). The consequence is that you just get a TypeError exception about __init__() missing 1 required positional argument: 'other_thing' and it completely masks the original exception.

Note that this behavior was changed in c8720e7696ca41f3262d5369365cc1bd72a216ca, it used to just re-raise the exception value. I don't know why it was changed.

I noticed this issue as a result of ​https://gitlab.com/alantrick/django-vox/issues/9

[Mariusz Felisiak]

Thanks for the report.

Regression in c8720e7696ca41f3262d5369365cc1bd72a216ca.
Reproduced at df46b329e0900e9e4dc1d60816c1dce6dfc1094e.

[Mariusz Felisiak]

Regression test.

[Tom Forbes]

PR: ​https://github.com/django/django/pull/11428

[Mariusz Felisiak <felisiak.mariusz@…>]

In 0344565:

Fixed #30516 -- Fixed crash of autoreloader when re-raising exceptions with custom signature.

Regression in c8720e7696ca41f3262d5369365cc1bd72a216ca.

[Mariusz Felisiak <felisiak.mariusz@…>]

In ace0bec8:

[2.2.x] Fixed #30516 -- Fixed crash of autoreloader when re-raising exceptions with custom signature.

Regression in c8720e7696ca41f3262d5369365cc1bd72a216ca.

Backport of 0344565179527d80990e2247e3be7c04aa8c43c8 from master