django 1.7 migrations: changes detected while nothing has changed ?

[Michael]

Hi,

Does anybody know how are changes detected by the ```makemigrations``` command in django 1.7?

It seems that I have a bug. The original post is on stackoverflow but no one has replied so I am trying here.

I have the issue that it always tells me there are changes for one of my field whereas there are not. When I run the command, it just writes the same migration file over and over with no changes.

The field is a custom field on which I implemented the deconstruct method and have some parameters that are objects so I used the deconstructible decorator.

I created a project on github that replicates the issue: https://github.com/YAmikep/django-testmigrations

What did I do wrong? Is this a bug?

Here is what I ran:

    /projects/testmigrations$ python manage.py makemigrations app1

    Migrations for 'app1':

      0001_initial.py:

        - Create model ModelA

    /projects/testmigrations$ python manage.py migrate

    Operations to perform:

      Apply all migrations: admin, contenttypes, auth, app1, sessions

    Running migrations:

      Applying contenttypes.0001_initial... OK

      Applying auth.0001_initial... OK

      Applying admin.0001_initial... OK

      Applying app1.0001_initial... OK

      Applying sessions.0001_initial... OK

    /projects/testmigrations$ python manage.py makemigrations

    Migrations for 'app1':

      0002_auto_20141014_2123.py:

        - Alter field field1 on modela

    /projects/testmigrations$ python manage.py makemigrations

    Migrations for 'app1':

      0003_auto_20141014_2123.py:

        - Alter field field1 on modela

The migration files 0002_auto_20141014_2123.py and 0003_auto_20141014_2123.py contain the exact same operations:

    operations = [

        migrations.AlterField(

            model_name='modela',

            name='field1',

            field=app1.models.CustomField(max_length=50, value_manager=app1.models.ValueManager(values=[app1.models.Value(val=1), app1.models.Value(val=2)])),

        ),

    ]

Thanks

Mike

[Markus Holtermann]

Hey Michael,

The problem seems to be the same as in #23473 https://code.djangoproject.com/ticket/23473 . Try adding a __eq__ method on the classes marked as deconstructible.

/Markus

--
Sent from my Android device with K-9 Mail. Please excuse my brevity.

[Michael]

Thanks, that fixed it.