New version of factory_boy does not work with a simple RelatedFactory case

Hi all, I upgraded to factory_boy 2.9.1 and a bunch of my tests are failing. I’ve isolated it down to a simple set of models. This was modeled on the documentation.

import factory

from django.db import models
from django.contrib.auth.models import User

from base.models import Account, Profile


class UserFactory(factory.django.DjangoModelFactory):
    class Meta:
        model = User

    # We pass in 'user' to link the generated Profile to our just-generated
    # User. This will call ProfileFactory(user=our_new_user), thus
    # skipping the SubFactory.
    profile = factory.RelatedFactory(
        'base.tests.factories.broken_factories.ProfileFactory', 'user')
    username = factory.Sequence(lambda n: 'user.username%d' % n)


class AccountFactory(factory.django.DjangoModelFactory):
    class Meta:
        model = Account

    admin = factory.SubFactory(UserFactory)
    name = factory.SelfAttribute('admin.email')


class ProfileFactory(factory.django.DjangoModelFactory):
    class Meta:
        model = Profile

    # We pass in None to prevent UserFactory from creating another
    # profile (this disables the RelatedFactory)
    user = factory.SubFactory(UserFactory, profile=None)

In my base.models, Account and Profile look like this, roughly:

class Account(models.Model):
    admin = models.ForeignKey(User, related_name='account_admin')
    name = models.CharField(max_length=64)


class Profile(models.Model):
    user = models.OneToOneField(User)

This fails in my tests when I instantiate AccountFactory() with no arguments. This is the error traceback and messaging:

DEBUG 2017-08-03 18:03:29,012 [factory.generate] [declarations.py::generate:392 ] SubFactory: Instantiating base.tests.factories.broken_factories.UserFactory(), create=<factory.builder.BuildStep object at 0x7faf4ef4bf50>
DEBUG 2017-08-03 18:03:29,012 [factory.generate] [declarations.py::evaluate:206 ] Sequence: Computing next value of <function <lambda> at 0x7faf54f447d0> for seq=0
DEBUG 2017-08-03 18:03:29,015 [factory.generate] [declarations.py::call:615 ] RelatedFactory: Generating base.tests.factories.broken_factories.ProfileFactory(<factory.builder.BuildStep object at 0x7faf4f9e3110>, user=<User: user.username0>)
DEBUG 2017-08-03 18:03:29,015 [factory.generate] [declarations.py::evaluate:58 ] LazyFunction: Evaluating <built-in function time> on <factory.builder.BuildStep object at 0x7faf4f76b410>
E
======================================================================
ERROR: test_broken_factory (base.tests.test_factories.FactoryTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/app/djapp/base/tests/test_factories.py", line 51, in test_broken_factory
    AccountFactory()
  File "/usr/local/lib/python2.7/site-packages/factory/base.py", line 46, in __call__
    return cls.create(**kwargs)
  File "/usr/local/lib/python2.7/site-packages/factory/base.py", line 568, in create
    return cls._generate(enums.CREATE_STRATEGY, kwargs)
  File "/usr/local/lib/python2.7/site-packages/factory/base.py", line 505, in _generate
    return step.build()
  File "/usr/local/lib/python2.7/site-packages/factory/builder.py", line 272, in build
    step.resolve(pre)
  File "/usr/local/lib/python2.7/site-packages/factory/builder.py", line 221, in resolve
    self.attributes[field_name] = getattr(self.stub, field_name)
  File "/usr/local/lib/python2.7/site-packages/factory/builder.py", line 363, in __getattr__
    extra=declaration.context,
  File "/usr/local/lib/python2.7/site-packages/factory/declarations.py", line 306, in evaluate
    return self.generate(step, defaults)
  File "/usr/local/lib/python2.7/site-packages/factory/declarations.py", line 395, in generate
    return step.recurse(subfactory, params, force_sequence=force_sequence)
  File "/usr/local/lib/python2.7/site-packages/factory/builder.py", line 233, in recurse
    return builder.build(parent_step=self, force_sequence=force_sequence)
  File "/usr/local/lib/python2.7/site-packages/factory/builder.py", line 293, in build
    context=postgen_context,
  File "/usr/local/lib/python2.7/site-packages/factory/declarations.py", line 617, in call
    return step.recurse(factory, passed_kwargs)
  File "/usr/local/lib/python2.7/site-packages/factory/builder.py", line 233, in recurse
    return builder.build(parent_step=self, force_sequence=force_sequence)
  File "/usr/local/lib/python2.7/site-packages/factory/builder.py", line 279, in build
    kwargs=kwargs,
  File "/usr/local/lib/python2.7/site-packages/factory/base.py", line 314, in instantiate
    return self.factory._create(model, *args, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/factory/django.py", line 165, in _create
    return manager.create(*args, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/django/db/models/manager.py", line 85, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/django/db/models/query.py", line 394, in create
    obj.save(force_insert=True, using=self.db)
  File "/usr/local/lib/python2.7/site-packages/django/db/models/base.py", line 807, in save
    force_update=force_update, update_fields=update_fields)
  File "/usr/local/lib/python2.7/site-packages/django/db/models/base.py", line 837, in save_base
    updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields)
  File "/usr/local/lib/python2.7/site-packages/django/db/models/base.py", line 923, in _save_table
    result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)
  File "/usr/local/lib/python2.7/site-packages/django/db/models/base.py", line 962, in _do_insert
    using=using, raw=raw)
  File "/usr/local/lib/python2.7/site-packages/django/db/models/manager.py", line 85, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/django/db/models/query.py", line 1076, in _insert
    return query.get_compiler(using=using).execute_sql(return_id)
  File "/usr/local/lib/python2.7/site-packages/django/db/models/sql/compiler.py", line 1107, in execute_sql
    cursor.execute(sql, params)
  File "/usr/local/lib/python2.7/site-packages/django/db/backends/utils.py", line 65, in execute
    return self.cursor.execute(sql, params)
  File "/usr/local/lib/python2.7/site-packages/django/db/utils.py", line 94, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/usr/local/lib/python2.7/site-packages/django/db/backends/utils.py", line 65, in execute
    return self.cursor.execute(sql, params)
  File "/usr/local/lib/python2.7/site-packages/django/db/backends/mysql/base.py", line 101, in execute
    return self.cursor.execute(query, args)
  File "/usr/local/lib/python2.7/site-packages/MySQLdb/cursors.py", line 174, in execute
    self.errorhandler(self, exc, value)
  File "/usr/local/lib/python2.7/site-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler
    raise errorclass, errorvalue
IntegrityError: (1062, "Duplicate entry '1' for key 'user_id'")

[domino14]

2.8.1 worked, and 2.9/2.9.1 don’t work with my code.

[rbarrois]

I’m closing this issue for now, since it seems to be due to an internals refactor messing up with an private-yet-slightly-documented method.

Please reopen it if the bug is still out there, or if the documentation fixes aren’t sufficient!