Having migrated most of our code across to pants, I'm now tackling the beast: Django. I'm struggling to get pytest-django to work, because it's failing while running migrations

elf = <django.db.backends.utils.CursorWrapper object at 0x7f1f6d967970>
sql = 'ALTER TABLE "dz_user_groups" ADD CONSTRAINT "dz_user_groups_group_id_2e149f2f_fk_auth_group_id" FOREIGN KEY ("group_id") REFERENCES "auth_group" ("id") DEFERRABLE INITIALLY DEFERRED'
params = ()
ignored_wrapper_args = (False, {'connection': <django.db.backends.postgresql.base.DatabaseWrapper object at 0x7f1f6f5bce20>, 'cursor': <django.db.backends.utils.CursorWrapper object at 0x7f1f6d967970>})

    def _execute(self, sql, params, *ignored_wrapper_args):
        self.db.validate_no_broken_transaction()
        with self.db.wrap_database_errors:
            if params is None:
                # params default might be backend specific.
                return self.cursor.execute(sql)
            else:
>               return self.cursor.execute(sql, params)
E               django.db.utils.ProgrammingError: relation "auth_group" does not exist

My guess is that the migrations for

django.contrib.auth

aren't running before it tries to apply our custom schema. If I run

pants run .../manage.py -- migrate

then all migrations are applied. I've got

string_imports

enabled, and have got the PANTS_EXECUTION_SLOT trick set up in a conftest. Pytest is creating a new DB per slot, and seems to be finding my migrations, but not applying auth, though it's sort of hard to tell in the absence of useful logs (thanks, django) Edit: fixed, thanks for 🦆

We have a Django plugin for pants, if there's room from improvement let us know. CC @happy-kitchen-89482

Yep, that did it. Just ran my first test. 🎉

The plugin is very early days, all it does right now is infer migration deps

Yeah, the example is great, but it's not super helpful if you already have a big old mess of Django. Last time I did this I gave up a couple of days in, this time it took me a couple of hours. I think it's just a question of experience.