          user_data = {}
          # Same as user_data but with foreign keys as fake model instances
          # instead of raw IDs.
          fake_user_data = {}
  
          # Do quick and dirty validation if --noinput
          if not options['interactive']:
              try:
                  if not username:
                      raise CommandError("You must use --%s with --noinput." % self.UserModel.USERNAME_FIELD)
 
</s> remove                 verbose_field_name = self.username_field.verbose_name
 </s> add 
        verbose_field_name = self.username_field.verbose_name
          user_data = {}
          # Same as user_data but with foreign keys as fake model instances
          # instead of raw IDs.
          fake_user_data = {}
        verbose_field_name = self.username_field.verbose_name
  
          # Do quick and dirty validation if --noinput
          if not options['interactive']:
              try:
                  if not username:
                      raise CommandError("You must use --%s with --noinput." % self.UserModel.USERNAME_FIELD)
keep keep keep add keep keep keep keep keep keep
 Fixed #28591 -- Added an error message for createsuperuser --username= (blank). 
django/contrib/auth/management/commands/createsuperuser.py