migrate_schemas not running

Using in requirements.txt

Django==3.1 django-tenant-schemas==1.10.0

In settings.py

[maxwellcc]

I discovered the reason for the problem. This error occurs in versions of Django greater than 3.0.9. So, I downgraded from version 3.1 to version 3.0.9

[danh91]

Hi guys, I am having the same problem too using Django 3.1 and DTS 1.10.0.

I looked around and realized that it has something to do with the changes in Django related to the skip_checks command option.

• First, in https://github.com/django/django/commit/6866c91b638de5368c18713fa851bfe56253ea55 --skip-check was introduced in Django BaseCommand causing the argument to be added twice since migrate adds it too. So to prevent the issue, requires_system_checks has to be set to False

• Now, https://code.djangoproject.com/ticket/31546 and https://github.com/django/django/pull/12910 introduced the notion of specific system checks. So requires_system_checks = [] is the new way of setting it to false

That said, here are different solutions/workarounds I found

1 - Add requires_system_checks = [] to migrate_schemas command class

class Command(SyncCommon):
    requires_system_checks = []
    ...

2 - Or customize BaseCommand.create_parser(prog_name, subcommand, **kwargs) to tell arg parser not to raise an exception when an argument is defined twice. (https://docs.python.org/3/library/argparse.html#conflict-handler)

class Command(SyncCommon):
   ...

    def create_parser(self, prog_name, subcommand, **kwargs):
        return super().create_parser(prog_name, subcommand, **{**kwargs, 'conflict_handler': 'resolve'})

    ...

---

I am more inclined to go with solution 1, I will make a PR with that. Please let me know what you think or if there is an even better way to approach it, I wouldn’t say I have a complete picture this is the first time I am using DTS.

In the meantime, you can locally override the migrate_schemas command to add the fix locally following https://docs.djangoproject.com/en/3.0/howto/custom-management-commands/

from tenant_schemas.management.commands.migrate_schemas import Command as MigrateSchemasCommand


class Command(MigrateSchemasCommand):
    requires_system_checks = []