Django Support: "pk" field has wrong type when using ForeignKey(…, primary_key=True)

[Feuermurmel]

Describe the Bug

In this example, Y's primary key is a foreign key to X:

from django.db.models import DO_NOTHING
from django.db.models import ForeignKey
from django.db.models import Model
from typing_extensions import reveal_type

class X(Model):
    pass

class Y(Model):
    x = ForeignKey(X, DO_NOTHING, primary_key=True)

reveal_type(Y().pk)

Y().pk is resolved as X, but the actual type in this case is int:

$ pyrefly check example.py 
 INFO revealed type: X [reveal-type]
  --> example.py:14:12
   |
14 | reveal_type(Y().pk)
   |            --------
 INFO 0 errors

When a Django model uses a foreign key as primary key, pk contains the "raw value" of the primary key, i.e. the primary key of the referenced model, instead of an instance of the referenced model.

Additional info:

$ python --version
Python 3.13.13
$ pyrefly --version
pyrefly 1.3.1
$ pip list
Package           Version
----------------- ---------------
asgiref           3.12.1
Django            6.1.1
django-stubs      6.1.1
django-stubs-ext  6.1.1
pip               26.1
pyrefly           1.3.1
sqlparse          0.6.0
types-PyYAML      6.0.12.20260906
typing_extensions 4.16.0 

Sandbox Link

No response

(Only applicable for extension issues) IDE Information

No response

[Feuermurmel]

I'm assuming that this is the same bug, but mentioning this for completeness: In the following example, Z().y_id is inferred to X instead of int. *_id fields never contain model instances.

from __future__ import annotations

from django.db.models import DO_NOTHING
from django.db.models import ForeignKey
from django.db.models import Model
from typing_extensions import reveal_type

class X(Model):
    pass

class Y(Model):
    x = ForeignKey(X, DO_NOTHING, primary_key=True)

class Z(Model):
    y = ForeignKey(Y, DO_NOTHING)

reveal_type(Z().y_id)