Can't set password on User during migration that depends on contrib.auth

[Markus Amalthea Magnuson]

I have an app with migrations that depend on the contrib.auth migrations. In one of my own migrations I want to create User objects and set their password. When trying to set a password for User object either through .set_password() or directly on creation through e.g. .create_superuser() I get this error:

AttributeError: 'User' object has no attribute 'set_password'

Attached is a test project. Create a virtual env with Django 1.9 and run ./manage.py migrate in it to see the error.

It seems like the password related methods are not available on the User object, only in the default manager, which I gather is not available in migrations. Is this intentional?

[Markus Amalthea Magnuson]

Test project with failing migration dependent on contrib.auth

[Marten Kenbeek]

It is expected behaviour that these methods are not available in your migrations. The reason is shortly explained in ​Historical models: arbitrary code can't be serialized, so there is no general way to make the historical methods available in your migrations.

To avoid this problem you can use the make_password function directly and set the hashed password on your user:

from django.contrib.auth.hashers import make_password

user.password = make_password('password')

[Tim Graham]

Was it a mistake to add use_in_migrations = True to the UserManager if it's not actually usable?

[Tim Graham]

Reopening per ​Markus's PR to solve this.

[Mariusz Felisiak <felisiak.mariusz@…>]

In 7af8f41:

Refs #26445 -- Allowed using UserManager.create_user()/create_superuser() in migrations.

Used app config to lookup user model in _create_user().

Thanks Markus Holtermann for the review and initial patch.
Thanks Simon Charette for the implementation idea.