Django: Migrations depend on removed 3rd-party module

Question

In my django project, I have been using django-taggit to add tagging capabilities to a model.

The migration adding tags also lists the initial taggit migration as dependency:

dependencies = [
    ('taggit', '0001_initial'),
    # …
]

At a later point in time, I have removed taggit everywhere, including INSTALLED_APPS.

The problem is that django can’t resolve that migration belonging to taggit, and raises an error.

What is the preferred solution in this scenario?

I can think of a two-step strategy:

1. keep taggit in INSTALLED_APPS until all servers running the project are up to date
2. squash migrations afterwards, so that the field does not show up any more, and only then remove taggit from INSTALLED_APPS

Answer 1

That's just about right. Note that you don't have to wait for all servers to be up-to-date before creating your squashed migration(s). From the documentation:

These files are marked to say they replace the previously-squashed migrations, so they can coexist with the old migration files, and Django will intelligently switch between them depending where you are in the history.

For the final step, you can even delete the old migration files, so there truly will be no more mention of taggit anywhere in your source:

You must then transition the squashed migration to a normal initial migration, by:

• Deleting all the migration files it replaces

• Removing the replaces argument in the Migration class of the squashed migration (this is how Django tells that it is a squashed migration)