I have a pretty big django project, and since I created the 100th migration within one of its apps today, I thought I'd finally do some squashing. It hasn't gone well, but I eventually got the data migrations cleaned up.
Finally, I run it, and it runs smack into a CircularDependencyError, as described here: https://code.djangoproject.com/ticket/23337 Basically, from what I understand, after the squash you have one migration that depends on various others from your other apps. Naturally, that totally falls over, because can't go from this series of migrations: app1: migration 1 app2: migration 1 app2: migration 2 app1: migration 2 To, well...any series of migrations in which migration 1&2 from app1 or app2 have been squashed. The docs have something to say about this*, but it feels like this must affect practically any biggish project. Stackoverflow also has a variety of dubious (and very complex) advice (read it and weep): https://stackoverflow.com/questions/37711402/circular-dependency-when-squashing-django-migrations So, my question is: Do people actually use squashmigrations with success? And if not, is it reasonable to consider deprecating it or fixing the bug, or updating the docs to loudly say it largely doesn't work? I'm surprised the issue above has so little movement since it was created seven years ago. Maybe it's just me? If not, it'd be nice to do something to help future people with ambitions of a simple squash. Thanks, Mike * Note that model interdependencies in Django can get very complex, and squashing may result in migrations that do not run; either mis-optimized (in which case you can try again with --no-optimize, though you should also report an issue), or with a CircularDependencyError, in which case you can manually resolve it. To manually resolve a CircularDependencyError, break out one of the ForeignKeys in the circular dependency loop into a separate migration, and move the dependency on the other app with it. If you’re unsure, see how makemigrations <https://docs.djangoproject.com/en/3.1/ref/django-admin/#django-admin-makemigrations> deals with the problem when asked to create brand new migrations from your models. In a future release of Django, squashmigrations <https://docs.djangoproject.com/en/3.1/ref/django-admin/#django-admin-squashmigrations> will be updated to attempt to resolve these errors itself. [Author's note: These sentences really leave me blowing in the wind...maybe I can figure out what they mean, I guess? I thought squashing was supposed to be easy.] -- You received this message because you are subscribed to the Google Groups "Django developers (Contributions to Django itself)" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-developers+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/django-developers/87f449bc-d653-427a-ac28-879ee0701c8bn%40googlegroups.com.
