A model outside an app causes inane error

[jMyles]

To reproduce:

Create a models.py in the root of a project (ie, next to manage.py). Create a class in it that inherits from django.db.models.Model.

This causes IndexError to be raised in the new because package_components will be only models, without the app name, ie, this line:

kwargs = {"app_label": package_components[app_label_index]}

Of course, the proper thing to do is to create an app, but new users may not realize this and, given this error, may not know on what topic to seek assistance.

[jMyles]

​https://github.com/django/django/pull/4066

[Tim Graham]

I believe #21680 is related.

[Tim Graham <timograham@…>]

In ac576e9f454db4942335a9a5df6168d31d4f98fe:

[1.8.x] Fixed #24287 -- Added friendly error if a model is in a models.py outside an installed app.

[Tim Graham <timograham@…>]

In eb406aa686ff1809903366ef6896037af2f1f69b:

[1.8.x] Silenced deprecation warning in refs #24287 test.