makemigrations raises AppRegistryNotReady instead of ImproperlyConfigured in Django 2.0

[Jaye Doepke]

In Django 2.0 with settings that should raise django.exceptions.ImproperlyConfigured, running manage.py makemigrations will raise django.exceptions.AppRegistryNotReady instead. This does not occur in Django 1.11.

Steps to Reproduce:

$ django-admin startproject example_project .
$ echo 'SECRET_KEY = None' >> example_project/settings.py
$ ./manage.py makemigrations
Traceback (most recent call last):
  File "./manage.py", line 15, in <module>
    execute_from_command_line(sys.argv)
  File "/home/jdoepke/Development/django_test/.venv/lib/python3.6/site-packages/django/core/management/__init__.py", line 371, in execute_from_command_line
    utility.execute()
  File "/home/jdoepke/Development/django_test/.venv/lib/python3.6/site-packages/django/core/management/__init__.py", line 365, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/jdoepke/Development/django_test/.venv/lib/python3.6/site-packages/django/core/management/__init__.py", line 216, in fetch_command
    klass = load_command_class(app_name, subcommand)
  File "/home/jdoepke/Development/django_test/.venv/lib/python3.6/site-packages/django/core/management/__init__.py", line 36, in load_command_class
    module = import_module('%s.management.commands.%s' % (app_name, name))
  File "/home/jdoepke/Development/django_test/.venv/lib/python3.6/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 994, in _gcd_import
  File "<frozen importlib._bootstrap>", line 971, in _find_and_load
  File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 665, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 678, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/home/jdoepke/Development/django_test/.venv/lib/python3.6/site-packages/django/core/management/commands/makemigrations.py", line 10, in <module>
    from django.db.migrations.autodetector import MigrationAutodetector
  File "/home/jdoepke/Development/django_test/.venv/lib/python3.6/site-packages/django/db/migrations/autodetector.py", line 11, in <module>
    from django.db.migrations.questioner import MigrationQuestioner
  File "/home/jdoepke/Development/django_test/.venv/lib/python3.6/site-packages/django/db/migrations/questioner.py", line 9, in <module>
    from .loader import MigrationLoader
  File "/home/jdoepke/Development/django_test/.venv/lib/python3.6/site-packages/django/db/migrations/loader.py", line 8, in <module>
    from django.db.migrations.recorder import MigrationRecorder
  File "/home/jdoepke/Development/django_test/.venv/lib/python3.6/site-packages/django/db/migrations/recorder.py", line 9, in <module>
    class MigrationRecorder:
  File "/home/jdoepke/Development/django_test/.venv/lib/python3.6/site-packages/django/db/migrations/recorder.py", line 22, in MigrationRecorder
    class Migration(models.Model):
  File "/home/jdoepke/Development/django_test/.venv/lib/python3.6/site-packages/django/db/models/base.py", line 100, in __new__
    app_config = apps.get_containing_app_config(module)
  File "/home/jdoepke/Development/django_test/.venv/lib/python3.6/site-packages/django/apps/registry.py", line 244, in get_containing_app_config
    self.check_apps_ready()
  File "/home/jdoepke/Development/django_test/.venv/lib/python3.6/site-packages/django/apps/registry.py", line 127, in check_apps_ready
    raise AppRegistryNotReady("Apps aren't loaded yet.")
django.core.exceptions.AppRegistryNotReady: Apps aren't loaded yet.

[Tim Graham]

Bisected to 13be45308045f522dfd1d0ff3da3cdc163bc521d.

[Claude Paroz]

This has been fixed by [d65b0f72de8d35617fe0554ddabc950c7f323eef].