Error when migrating new User model

Question

Just created a User model in my models.py to save the users in the database. The model looks like this:

class User(AbstractBaseUser, PermissionsMixin):
    username = models.CharField(_('username'), max_length=30, unique=True,
        validators=[
      validators.RegexValidator(re.compile('^[\w.@+-]+$'), _('Enter a valid username.'), _('invalid'))
    ])
    first_name = models.CharField(_('first name'), max_length=30, blank=True, null=True)
    last_name = models.CharField(_('last name'), max_length=30, blank=True, null=True)
    email = models.EmailField(_('email address'), max_length=255)
    is_staff = models.BooleanField(_('staff status'), default=False,)
    is_active = models.BooleanField(_('active'), default=False,)
    date_joined = models.DateTimeField(_('date joined'), default=timezone.now)

    USERNAME_FIELD = 'username'
    REQUIRED_FIELDS = ['email',]

    class Meta:
        verbose_name = _('user')
        verbose_name_plural = _('users')

    def get_full_name(self):
        full_name = '%s %s' % (self.first_name, self.last_name)
        return full_name.strip()

    def get_short_name(self):
        return self.first_name

    def email_user(self, subject, message, from_email=None):
        send_mail(subject, message, from_email, [self.email])

I've also added in settings.py this piece of code:

AUTH_USER_MODEL = "myapp.User"

However, when I try to makemigrations for applying the changes, it appears this error:

Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\core\management\__init__.py", line 353, in execute_from_command_line
    utility.execute()
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\core\management\__init__.py", line 345, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\core\management\base.py", line 348, in run_from_argv
    self.execute(*args, **cmd_options)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\core\management\base.py", line 399, in execute
    output = self.handle(*args, **options)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\core\management\commands\makemigrations.py", line 105, in handle
    loader.project_state(),
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\migrations\loader.py", line 338, in project_state
    return self.graph.make_state(nodes=nodes, at_end=at_end, real_apps=list(self.unmigrated_apps))
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\migrations\graph.py", line 280, in make_state
    project_state = self.nodes[node].mutate_state(project_state, preserve=False)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\migrations\migration.py", line 88, in mutate_state
    operation.state_forwards(self.app_label, new_state)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\migrations\operations\models.py", line 158, in state_forwards
    apps = state.apps
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\utils\functional.py", line 33, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\migrations\state.py", line 162, in apps
    return StateApps(self.real_apps, self.models)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\migrations\state.py", line 235, in __init__
    raise ValueError(self._pending_models_error(pending_models))
ValueError: Unhandled pending operations for models:
  myapp.user (referred to by fields: admin.LogEntry.user)

So I'm looking for info for possible solutions or causes for this error but can't figure out why it happens. May it have to be a problem with some previous migration? (if so, I have no clue of which nor why). I'd add more information if needed, but I'd really appreciate any clue of the cause of this error.

Answer 1

The custom user docs specifically warn against switching User model after you have already created migrations; there's too much dependency for that to work properly. You may need to delete your existing db and migrations and start from scratch.