Using lambdas in model field arguments is not compatible with migrations

[George]

According to the documentation of migrations:

Django cannot serialize:

    Nested classes
    Arbitrary class instances (e.g. MyClass(4.3, 5.7))
    Lambdas

The more complex example and the references of the documentation should mention it.

from django.db.models import CharField, DateField, ForeignKey, Model
from django.contrib.auth.models import User
from autoslug import AutoSlugField

class Article(Model):
    title = CharField(max_length=200)
    pub_date = DateField(auto_now_add=True)
    author = ForeignKey(User)
    slug = AutoSlugField(populate_from=lambda instance: instance.title,
                         unique_with=['author__name', 'pub_date__month'],
                         slugify=lambda value: value.replace(' ','-'))

[Paul Albrecht]

See report #29