Changing upload_to on a filefield creates a migration despite not changing the database at all

[Greg Brown]

upload_to is commonly set in django settings, and changing the setting generates a "Your models have changes that are not yet reflected in a migration..." warning until you create an (effectively no-op) migration. This really shouldn't trigger a migration, because upload_to is solely used to generate a file path, and doesn't change the underlying field at all.

It's not much of a problem for local apps, you just end up with extra migrations, but it happens with 3rd-party apps too.

[Tim Graham]

This is by design; please see ​https://docs.djangoproject.com/en/stable/topics/migrations/#historical-models.