AssertionError: Type info for django.db.models.query._QuerySet missing

[alexlatif]

VScode mypy Django QuerySet error

Hi, I am not using anything out of the ordinary other than mypy and django-stubs. When my VScode runs mypy it crashes with this traceback below.

  File "/venv/lib/python3.11/site-packages/mypy_django_plugin/main.py", line 50, in transform_model_class
    process_model_class(ctx, django_context)
  File "/venv/lib/python3.11/site-packages/mypy_django_plugin/transformers/models.py", line 674, in process_model_class
    initializer_cls(ctx, django_context).run()
  File "/venv/lib/python3.11/site-packages/mypy_django_plugin/transformers/models.py", line 96, in run
    self.run_with_model_cls(model_cls)
  File "/venv/lib/python3.11/site-packages/mypy_django_plugin/transformers/models.py", line 377, in run_with_model_cls
    fallback_manager_info = self.get_or_create_manager_with_any_fallback()
                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib/python3.11/site-packages/mypy_django_plugin/transformers/models.py", line 131, in get_or_create_manager_with_any_fallback
    fallback_queryset = self.get_or_create_queryset_with_any_fallback()
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib/python3.11/site-packages/mypy_django_plugin/transformers/models.py", line 181, in get_or_create_queryset_with_any_fallback
    assert base_queryset_info, f"Type info for {fullnames.QUERYSET_CLASS_FULLNAME} missing"
AssertionError: Type info for django.db.models.query._QuerySet missing

mypy almost always seems to crash with VScode open. I had originally patched files here

File "/venv/lib/python3.11/site-packages/mypy_django_plugin/transformers/models.py", line 155, in get_or_create_queryset_with_any_fallback

But it was a very crude way of getting it to work.

It does on occasion work for a few minutes (or at least not error) but I cannot seem to replicate its success on command.

I have been through several open and closed issues closely related but can't find anything similar to what I am facing.

I also don't know if this bug will be covered by this release. - #1316

Would be grateful for any help on this as its stopping my VScode from running mypy on my code and get a popup appear everytime I do a code change.

System information

• OS: Mac M2 Ventura 13.1
• python version: 3.11.0
• django version: 4.1.4
• mypy version: 0.991
• django-stubs version: 1.13.0
• django-stubs-ext version: 0.7.0
• vscode version: 1.74.3
• 'vscode-mypy-extension` version: v0.2.2

[intgr]

I also don't know if this bug will be covered by this release. - #1316

I'm afraid not, sorry. The only fix to plugin code that's currently currently merged on master is #1317.

We currently don't have people actively working on mypy-plugin bugs, besides some drive-by contributors.

[ljodal]

This looks a lot like code I've written 😇 Do you have any additional pointers to how this happens? I've never seen this bug before, but it seems a bit strange to me. Basically the error means that mypy has not loaded the Django models when checking a model file, which seems strange. I assumed that would always be the case. I can throw together a potential fix that you can try

[alexrudd2]

Can reproduce with a traceback at the exact same line. Running CLI mypy (no VSCode) in a pipenv.

• OS: Mac M1 Ventura 13.1
• python version: 3.10.9
• mypy version: 1.1.1

❯ pipenv graph | grep django
django-crispy-forms==1.14.0
django-extensions==3.2.1
django-filter==22.1
django-maintenance-mode==0.18.0
django-phone-field==1.8.1
django-select2==8.1.0
  - django [required: >=3.2, installed: 4.1.7]
  - django-appconf [required: >=0.6.0, installed: 1.0.5]
    - django [required: Any, installed: 4.1.7]
django-tempus-dominus==5.1.2.17
  - django [required: Any, installed: 4.1.7]
djangorestframework-api-key==2.3.0
djangorestframework-csv==2.1.1
  - djangorestframework [required: Any, installed: 3.14.0]
    - django [required: >=3.0, installed: 4.1.7]
djangorestframework-datatables==0.7.0
  - djangorestframework [required: >=3.7.0, installed: 3.14.0]
    - django [required: >=3.0, installed: 4.1.7]
djangorestframework-stubs==1.9.1
  - django-stubs [required: >=1.13.0, installed: 1.15.0]
    - django [required: Any, installed: 4.1.7]
    - django-stubs-ext [required: >=0.7.0, installed: 0.7.0]
      - django [required: Any, installed: 4.1.7]

[ljodal]

Do you have an example of a file that triggers this? I'm not able to reproduce this, so I'm not really able to fix it until I can understand how/why it fails

[alexrudd2]

Aha. The problem is caused by having both django-stubs and django-types installed at the same time.

It persists even after uninstalling django-types (some sort of mypy cache, I assume).
To fix, both django-types and django-stubs must be uninstalled, and then django-stubs re-installed.

I realize django-types is a fork, and it doesn't make sense to use both. Still, it's pretty easy to get confused as a newcomer. Is it possible to have the packages explicitly conflict?

[ljodal]

Ah, thanks! I can try to see if I can make it handle that case or at the very least point to this issue when it pops up

[alexlatif]

@ljodal hello mate, sorry for not getting back to you earlier as I didnt see the notification. I dont actually have django-types. What can I provide to help debug this? I am still running without the VScode mypy extension currently to avoid the error.

[reeteshranjan]

Have you re-checked if you are using the right python virtual environment? I faced this and another issue when I moved to a new laptop with Ventura, and did not select the right virtual env with my project dependencies installed, but the system python interpreter.