Re: RenameField with django 2.0: AttributeError: 'ManyToManyRel' object has no attribute 'field_name'

Hello there,

This looks like a regression in Django 2.0 caused by 095c1aaa[0].

Please file a new ticket mentioning it's a regression in Django 2.0
and mark it as a release blocker. [1]

Thanks,
Simon

[0] https://github.com/django/django/commit/095c1aaa898bed40568009db836aa8434f1b983d
[1] https://code.djangoproject.com/newticket

Le lundi 4 décembre 2017 08:19:50 UTC-5, edigi...@arpae.it a écrit :

With Django==2.0, a RenameField on a model which has a reverse many to many relationship raises an exception:

    AttributeError: 'ManyToManyRel' object has no attribute 'field_name'

The same migration with Django==1.11 terminates successfully.

Migrations are automatically generated by `manage.py makemigrations`.

Am I missing something?

Below the code and the commands to reproduce the problem:

# myapp/models.py

from django.db import models

class ModelA(models.Model):

    new_name = models.IntegerField()

class ModelB(models.Model):

    model_as = models.ManyToManyField('ModelA')

# myapp/migrations/0001_initial.py

from django.db import migrations, models

class Migration(migrations.Migration):

    initial = True

    dependencies = [

    ]

    operations = [

        migrations.CreateModel(

            name='ModelA',

            fields=[

                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),

                ('old_name', models.IntegerField()),

            ],

        ),

        migrations.CreateModel(

            name='ModelB',

            fields=[

                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),

                ('model_as', models.ManyToManyField(to='myapp.ModelA')),

            ],

        ),

    ]

# myapp/migrations/0002_auto_20171204_1012.py

from django.db import migrations

class Migration(migrations.Migration):

    dependencies = [

        ('myapp', '0001_initial'),

    ]

    operations = [

        migrations.RenameField(

            model_name='modela',

            old_name='old_name',

            new_name='new_name',

        ),

    ]

$ ./manage.py migrate

Operations to perform:

  Apply all migrations: admin, auth, contenttypes, myapp, sessions

Running migrations:

  Applying contenttypes.0001_initial... OK

  Applying auth.0001_initial... OK

  Applying admin.0001_initial... OK

  Applying admin.0002_logentry_remove_auto_add... OK

  Applying contenttypes.0002_remove_content_type_name... OK

  Applying auth.0002_alter_permission_name_max_length... OK

  Applying auth.0003_alter_user_email_max_length... OK

  Applying auth.0004_alter_user_username_opts... OK

  Applying auth.0005_alter_user_last_login_null... OK

  Applying auth.0006_require_contenttypes_0002... OK

  Applying auth.0007_alter_validators_add_error_messages... OK

  Applying auth.0008_alter_user_username_max_length... OK

  Applying auth.0009_alter_user_last_name_max_length... OK

  Applying myapp.0001_initial... OK

  Applying myapp.0002_auto_20171204_1012...Traceback (most recent call last):

  File "./manage.py", line 15, in <module>

    execute_from_command_line(sys.argv)

  File "/home/edg/src/example/env/lib/python3.6/site-packages/django/core/management/__init__.py", line 371, in execute_from_command_line

    utility.execute()

  File "/home/edg/src/example/env/lib/python3.6/site-packages/django/core/management/__init__.py", line 365, in execute

    self.fetch_command(subcommand).run_from_argv(self.argv)

  File "/home/edg/src/example/env/lib/python3.6/site-packages/django/core/management/base.py", line 288, in run_from_argv

    self.execute(*args, **cmd_options)

  File "/home/edg/src/example/env/lib/python3.6/site-packages/django/core/management/base.py", line 335, in execute

    output = self.handle(*args, **options)

  File "/home/edg/src/example/env/lib/python3.6/site-packages/django/core/management/commands/migrate.py", line 200, in handle

    fake_initial=fake_initial,

  File "/home/edg/src/example/env/lib/python3.6/site-packages/django/db/migrations/executor.py", line 117, in migrate

    state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)

  File "/home/edg/src/example/env/lib/python3.6/site-packages/django/db/migrations/executor.py", line 147, in _migrate_all_forwards

    state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)

  File "/home/edg/src/example/env/lib/python3.6/site-packages/django/db/migrations/executor.py", line 244, in apply_migration

    state = migration.apply(state, schema_editor)

  File "/home/edg/src/example/env/lib/python3.6/site-packages/django/db/migrations/migration.py", line 122, in apply

    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)

  File "/home/edg/src/example/env/lib/python3.6/site-packages/django/db/migrations/operations/fields.py", line 304, in database_forwards

    to_model._meta.get_field(self.new_name),

  File "/home/edg/src/example/env/lib/python3.6/site-packages/django/db/backends/sqlite3/schema.py", line 81, in alter_field

    any(r.field_name == old_field.name for r in model._meta.related_objects)):

  File "/home/edg/src/example/env/lib/python3.6/site-packages/django/db/backends/sqlite3/schema.py", line 81, in <genexpr>

    any(r.field_name == old_field.name for r in model._meta.related_objects)):

AttributeError: 'ManyToManyRel' object has no attribute 'field_name'

$ pip freeze

Django==2.0

pytz==2017.3

--
You received this message because you are subscribed to the Google Groups "Django users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to django-users+unsubscribe@googlegroups.com.
To post to this group, send email to django-users@googlegroups.com.
Visit this group at https://groups.google.com/group/django-users.
To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/478a96d1-b3ae-4ed4-88ae-f705f4c1f4af%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.