title: Django Social Auth not working with custom user setup
body: <p>I've been having a heck of a time getting django and django-social-auth to play nicely with a custom user and custom user manager. I've found many posts about this, but nothing seems to be working.</p>
  
  <p>Here are the settings:</p>
  
  <pre><code>LOGIN_URL                         = '/login/'
  LOGIN_ERROR_URL                   = '/login/error/'
  LOGIN_REDIRECT_URL                = '/'
  LOGOUT_REDIRECT_URL               = '/'
  
  SOCIAL_AUTH_COMPLETE_URL_NAME = 'socialauth_complete'
  SOCIAL_AUTH_ASSOCIATE_URL_NAME = 'socialauth_associate_complete'
  SOCIAL_AUTH_RAISE_EXCEPTIONS = False
  SOCIAL_AUTH_FORCE_POST_DISCONNECT = True
  SOCIAL_AUTH_USERNAME_IS_FULL_EMAIL = True
  
  AUTH_USER_MODEL                   = 'auth.MyUser'
  SOCIAL_AUTH_USER_MODEL            = 'auth.MyUser'
  
  FACEBOOK_APP_ID                   = 'xxxx'
  FACEBOOK_API_SECRET               = 'xxxx'
  FACEBOOK_EXTENDED_PERMISSIONS     = ['user_birthday','email','user_about_me','user_education_history','user_events','user_likes','user_subscriptions','user_groups','publish_actions','read_friendlists','user_relationships','user_relationship_details','publish_stream']
  
  AUTHENTICATION_BACKENDS = (
      'social_auth.backends.facebook.FacebookBackend',
      'django.contrib.auth.backends.ModelBackend',
  )
  
  SOCIAL_AUTH_PIPELINE = (
    'social_auth.backends.pipeline.social.social_auth_user',
    'social_auth.backends.pipeline.social.load_extra_data',
    'social_auth.backends.pipeline.user.get_username',
    'social_auth.backends.pipeline.user.create_user',
    'social_auth.backends.pipeline.social.associate_user',
    'social_auth.backends.pipeline.user.update_user_details'
  )
  </code></pre>
  
  <p>Here is my model</p>
  
  <pre><code>from django.db import models
  from django.contrib.auth.models import (
      BaseUserManager, AbstractBaseUser
  )
  
  class MyUserManager(BaseUserManager):
      def create_user(self, username, email, password=None):
          """
          Creates and saves a User with the given email and password.
          """
          if not email:
             raise ValueError('Users must have an email address')
  
          user = self.model(
              email=MyUserManager.normalize_email(email),
          )
  
          user.set_password(password)
          user.save(using=self._db)
          return user
  
  class MyUser(AbstractBaseUser):
      email = models.EmailField(
          verbose_name='Email address',
          max_length=255,
          unique=True,
          db_index=True,
      )
      is_active = models.BooleanField(default=True)
      is_admin = models.BooleanField(default=False)
  
      objects = MyUserManager()
  
      def has_perm(self, perm, obj=None):
          "Does the user have a specific permission?"
          # Simplest possible answer: Yes, always
          return True
  
      def has_module_perms(self, app_label):
          "Does the user have permissions to view the app `app_label`?"
          # Simplest possible answer: Yes, always
          return True
  
      @property
      def is_staff(self):
          "Is the user a member of staff?"
          # Simplest possible answer: All admins are staff
          return self.is_admin
  
      class Meta:
          db_table = 'customUser'
  </code></pre>
  
  <p>From what I can gather the creation of the user is erroring somewhere and forcing the django auth plugin to look for a non existant error backend. This issue resolves itself if I do not use a custom user/manager.</p>
  
  <p>Any assistance on what I may be missing here would be appreciated.</p>