Django: Make user email required

add in models.py

from django.contrib.auth.models import User

User._meta.get_field('email')._unique = True
User._meta.get_field('email').blank = False
User._meta.get_field('email').null = False

I have to answer my question because now I know the solution:

The way I described in the start post should work. The docs are just wrong: https://code.djangoproject.com/ticket/29192