Plugin calls `ready` of all installed apps

Bug report

What’s wrong

django-stubs calls apps.populate(settings.INSTALLED_APPS) which in turn calls ready on all apps. And that requires all imports to be present and even can execute SQL queries.

  File "/usr/local/lib/python3.8/site-packages/mypy_django_plugin/main.py", line 71, in __init__
    self.django_context = DjangoContext(self.plugin_config.django_settings_module)
  File "/usr/local/lib/python3.8/site-packages/mypy_django_plugin/django/context.py", line 97, in __init__
    apps, settings = initialize_django(self.django_settings_module)
  File "/usr/local/lib/python3.8/site-packages/mypy_django_plugin/django/context.py", line 81, in initialize_django
    apps.populate(settings.INSTALLED_APPS)
  File "/usr/local/lib/python3.8/site-packages/django/apps/registry.py", line 122, in populate
    app_config.ready()
...
  File "/usr/local/lib/python3.8/site-packages/django/db/backends/utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
django.db.utils.ProgrammingError: relation "..." does not exist

How is that should be

What’s the purpose of calling apps.populate? would it be possible to avoid calling ready on apps and still do what django-stubs needs to do? If I understand correctly, you need only imports to be executed, right? If it sounds interesting I could look into mocking app_config.ready() calls.

Related: #1060

System information

• OS: Linux Mint
• python version: 3.8.13
• django version: 3.2.15
• mypy version: 0.971
• django-stubs version: 1.12.0
• django-stubs-ext version: 0.5.0

[flaeppe]

Haha, yes, you’re right. It’s me being confused, mixing up what’s runtime and not

[orsinium]

And that’s the big difference between mypy and django-stubs. The latter actually executes the code, and so potentially suffers from all possible slow-downs, loops, and side-effects. And the issue is about finding a way to avoid it.