"./manage.py migrate" causes "maximum recursion depth exceeded" error

[Berker Peksag]

With the latest master (0247c9b08f8da4a2d93b9cede6c615011552b55a), I'm getting the following exception:

[snipped]

  File "/home/berker/projects/django/django/core/management/commands/migrate.py", line 62, in _run_checks
    issues.extend(super(Command, self).check(**kwargs))
  File "/home/berker/projects/django/django/core/management/base.py", line 385, in check
    include_deployment_checks=include_deployment_checks,
  File "/home/berker/projects/django/django/core/management/commands/migrate.py", line 61, in _run_checks
    issues = run_checks(tags=[Tags.database])
  File "/home/berker/projects/django/django/core/checks/registry.py", line 81, in run_checks
    new_errors = check(app_configs=app_configs)
  File "/home/berker/projects/django/django/core/checks/database.py", line 9, in check_database_backends
    for conn in connections.all():
  File "/home/berker/projects/django/django/db/utils.py", line 226, in all
    return [self[alias] for alias in self]
RuntimeError: maximum recursion depth exceeded

I created a sample project to demonstrate the bug: ​https://bitbucket.org/berkerpeksag/django-bug You can see the full output of ./manage.py migrate at ​https://bitbucket.org/berkerpeksag/django-bug/src/b527f36d15c4e68168621dd39db164a8beaf905e/tdj/log.txt?at=master&fileviewer=file-view-default

The project is simple. I only created a model: ​https://bitbucket.org/berkerpeksag/django-bug/src/b527f36d15c4e68168621dd39db164a8beaf905e/tdj/polls/models.py?at=master&fileviewer=file-view-default

I believe the cause of the issue is at ​https://github.com/django/django/commit/0d3c616fbb2f49fa7ff6809e5a6777275352b35b#diff-e835ddfb52774b39749788a0d046e477R62 If I replace line 62 with

issues.extend(super(Command, self)._run_checks(**kwargs))

it works as expected.

[Berker Peksag]

A simple fix (without tests) can be found at ​https://github.com/django/django/compare/master...berkerpeksag:26492-migrate-recursion

[Tim Graham]

Also confirmed in #26490 (closed that as a duplicate).

[Berker Peksag]

​https://github.com/django/django/pull/6445

[Tim Graham <timograham@…>]

In 93deb16:

Fixed #26492 -- Fixed "maximum recursion depth exceeded" migrate error.

A regression introduced in 0d3c616fbb2f49fa7ff6809e5a6777275352b35b;
refs #26351.