Custom and Unmanaged User Model/Lagacy User Table

I am trying to make django-guardian work with my custom User model. The model is inherited from AbstractUser and also from GuardianUserMixin. Here is the User model:

class User(AbstractUser, GuardianUserMixin):

    class Meta:
        managed = False
        db_table = 'users'

The problem I am facing is when I am checking permissions. For example here request.user.has_perm(...)

Here is the error message:

ProgrammingError at /manageDb/mira/follow/14/ relation "users_groups" does not exist LINE 1: ...sion"."group_id" = "auth_group"."id" ) INNER JOIN "users_gro...

Traceback:

    File "/home/khajvah/Project/mira_website/manageDb/views.py" in delete
  486.             if request.user.has_perm('follow', follow_object):
File "/usr/local/lib/python3.4/dist-packages/django/contrib/auth/models.py" in has_perm
  353.         return _user_has_perm(self, perm, obj)
File "/usr/local/lib/python3.4/dist-packages/django/contrib/auth/models.py" in _user_has_perm
  281.             if backend.has_perm(user, perm, obj):
File "/usr/local/lib/python3.4/dist-packages/guardian/backends.py" in has_perm
  89.         return check.has_perm(perm, obj)
File "/usr/local/lib/python3.4/dist-packages/guardian/core.py" in has_perm
  54.         return perm in self.get_perms(obj)
File "/usr/local/lib/python3.4/dist-packages/guardian/core.py" in get_perms
  110.                 perms = list(set(chain(user_perms, group_perms)))
File "/usr/local/lib/python3.4/dist-packages/django/db/models/query.py" in __iter__
  162.         self._fetch_all()
File "/usr/local/lib/python3.4/dist-packages/django/db/models/query.py" in _fetch_all
  965.             self._result_cache = list(self.iterator())
File "/usr/local/lib/python3.4/dist-packages/django/db/models/query.py" in iterator
  1217.             for row in compiler.results_iter():
File "/usr/local/lib/python3.4/dist-packages/django/db/models/sql/compiler.py" in results_iter
  794.             results = self.execute_sql(MULTI)
File "/usr/local/lib/python3.4/dist-packages/django/db/models/sql/compiler.py" in execute_sql
  840.             cursor.execute(sql, params)
File "/usr/local/lib/python3.4/dist-packages/django/db/backends/utils.py" in execute
  79.             return super(CursorDebugWrapper, self).execute(sql, params)
File "/usr/local/lib/python3.4/dist-packages/django/db/backends/utils.py" in execute
  64.                 return self.cursor.execute(sql, params)
File "/usr/local/lib/python3.4/dist-packages/django/db/utils.py" in __exit__
  97.                 six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/usr/local/lib/python3.4/dist-packages/django/utils/six.py" in reraise
  658.             raise value.with_traceback(tb)
File "/usr/local/lib/python3.4/dist-packages/django/db/backends/utils.py" in execute
  64.                 return self.cursor.execute(sql, params)

The problem seems to be that guardian is making query on a table users_groups, which doesn't exist, instead, it is called auth_groups, which is created by django.auth. So the problem comes down to specifying the user group model in guardian

I made a hacky solution. What was guardian doing is expecting a ManyToMany relationship with User and auth_group. AbstractUser does this by default but since I have manually given managed = False and also a db_table, Django wasn't creating the relationship when migrating, so I created a intermediate model for the relationship and here is how a part of my model.py looks like:

class User(AbstractBaseUser, PermissionsMixin, GuardianUserMixin):

    username=models.CharField(unique=True, max_length=123)
    date_joined = models.DateTimeField(default=datetime.now())
    email=models.CharField(unique=True, max_length=125)
    first_name=models.CharField(max_length=128)
    last_name=models.CharField(max_length=128)

    is_staff = models.NullBooleanField(null=True)
    is_active = models.NullBooleanField(null=True)

    USERNAME_FIELD='username'
    REQUIRED_FIELDS = ['password', 'email', 'first_name', 'last_name']

    objects = UserManager()
    class Meta:
        managed = False
        db_table = 'users'

class GroupUser(models.Model):
    group = models.ForeignKey(Group)
    user = models.ForeignKey(User)

    class Meta:
        db_table = 'users_groups'

The key thing is to have the group table to have the correct name. I.e. guardian is waiting for userTableName_groups.