I'm getting an error building factories with subfactories to test django models. With models:

class Space(ExportModelOperationsMixin('space'), models.Model):
    name = models.CharField(max_length=128, default='Default')  

class ShoppingListEntry(models.Model):
    food = models.ForeignKey(Food)
    space = models.ForeignKey(Space)

class Food(models.Model):
    name = models.CharField(max_length=128)
    description = models.TextField(default='', blank=True)
    space = models.ForeignKey(Space)

and fixtures:

class SpaceFactory(factory.django.DjangoModelFactory):
    name = factory.LazyAttribute(lambda x: faker.word())

class FoodFactory(factory.django.DjangoModelFactory):
    name = factory.LazyAttribute(lambda x: faker.sentence(nb_words=3))
    description = factory.LazyAttribute(lambda x: faker.sentence(nb_words=10))
    space = factory.SubFactory(SpaceFactory)

class ShoppingListEntryFactory(factory.django.DjangoModelFactory):
    food = factory.SubFactory(FoodFactory, space=factory.SelfAttribute('..space'))
    space = factory.SubFactory(SpaceFactory)

and test

register(SpaceFactory, 'space_1')
register(ShoppingListEntryFactory, 'shopping_list_entry', space=LazyFixture('space_1'))
def test_list_space(shopping_list_entry):
    assert 1 == 1

throws the following error

Failed with Error: [undefined]failed on setup with
  def test_list_space(sle_1):
file <string>, line 2: source code not available
file <string>, line 2: source code not available
E       fixture 'food__name' not found

I'm struggling to figure out how to troubleshoot this.