id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
32893	Missing import statement in generated migration (NameError: name 'models' is not defined)	Jaap Joris Vens	Abhyudai	"I found a bug in Django's latest release: 3.2.4. 

Given the following contents of `models.py`:

{{{
from django.db import models

class MyField(models.TextField):
    pass

class MyBaseModel(models.Model):
    class Meta:
        abstract = True

class MyMixin:
    pass

class MyModel(MyMixin, MyBaseModel):
    name = MyField(primary_key=True)
}}}

The `makemigrations` command will generate the following migration file:

{{{
# Generated by Django 3.2.4 on 2021-06-30 19:13

import app.models
from django.db import migrations


class Migration(migrations.Migration):

    initial = True

    dependencies = [
    ]

    operations = [
        migrations.CreateModel(
            name='MyModel',
            fields=[
                ('name', app.models.MyField(primary_key=True, serialize=False)),
            ],
            options={
                'abstract': False,
            },
            bases=(app.models.MyMixin, models.Model),
        ),
    ]
}}}

Which will then fail with the following error:

{{{
  File ""/home/jj/django_example/app/migrations/0001_initial.py"", line 7, in <module>
    class Migration(migrations.Migration):
  File ""/home/jj/django_example/app/migrations/0001_initial.py"", line 23, in Migration
    bases=(app.models.MyMixin, models.Model),
NameError: name 'models' is not defined
}}}

Expected behavior: Django generates a migration file that is valid Python.

Actual behavior: Django generates a migration file that is missing an import statement.

I think this is a bug of the module `django.db.migrations.writer`, but I'm not sure. I will be happy to assist with debugging.

Thanks for your attention,
Jaap Joris"	Bug	closed	Migrations	dev	Normal	fixed	migrations writer missing import		Ready for checkin	1	0	0	0	0	0