AttributeError: 'CharField' object has no attribute 'swappable_setting'

[Baptiste Mispelon]

Here's how to reproduce:

Create an app with a simple models.py (and put it in settings.INSTALLED_APPS):

from django.db import models

class Foo(models.Model):
    pass

Run makemigrations and then migrate.

Then change the Foo model to be:

class Foo(models.Model):
    foo = models.CharField(max_length=10, default='')

After that, running manage.py makemigrations breaks with the following traceback:

Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "./django/core/management/__init__.py", line 427, in execute_from_command_line
    utility.execute()
  File "./django/core/management/__init__.py", line 419, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "./django/core/management/base.py", line 287, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "./django/core/management/base.py", line 336, in execute
    output = self.handle(*args, **options)
  File "./django/core/management/commands/makemigrations.py", line 80, in handle
    changes = autodetector.changes(graph=loader.graph, trim_to_apps=app_labels or None)
  File "./django/db/migrations/autodetector.py", line 33, in changes
    changes = self._detect_changes()
  File "./django/db/migrations/autodetector.py", line 236, in _detect_changes
    swappable_setting = new_apps.get_model(app_label, model_name)._meta.get_field_by_name(field_name)[0].swappable_setting
AttributeError: 'CharField' object has no attribute 'swappable_setting'

Breakage was introduced in commit 11c021336c8cb1c92be998f1a44c89a746275107.

[Baptiste Mispelon]

Failing test case and tentative fix there: ​https://github.com/django/django/pull/2270

[Baptiste Mispelon <bmispelon@…>]

In 6873eeeefbc3a081c98351ff25b4cdc42dbf3d7d:

Fixed #22030 -- Don't assume that all fields have a swappable_setting attribute.

[Andrew Godwin <andrew@…>]

In 3c547a423f5394d816b5a942570abd904f07bfba:

Merge pull request #2270 from bmispelon/ticket-22030

Fixed #22030 -- Don't assume that all fields have a swappable_setting at...