django - Migrate model while adding user foreign key -

so have model added user field foreign key user model

from django.db import models django.contrib.auth.models import user django.conf import settings  class post(models.model):     url = models.urlfield()     title = models.charfield(max_length=140)     user = models.foreignkey(settings.auth_user_model) 

than run

python3 manage.py makemigrations 

and get:

you trying add non-nullable field 'user' comment without    default;  can't (the database needs populate existing rows). please select fix:     1) provide one-off default (will set on existing rows)     2) quit, , let me add default in models.py 

i understand need give default user don't how that.

p.s. django version - 1.8.3

ok, happens migration utility's question hadn't appeared intuitive enough me. migration utility asking required fields of user model. need type in data 3 times (for username, password , email). problem utility isn't saying field expecting.