Textual "to" parameter of ForeignKey fails to resolve if placed in abstract model

[Vitalik Verhovodov]

import django
from django.conf import settings

settings.configure(DEBUG=True)
django.setup()

from django.db import models


SHOULD_I_FAIL = True  # switch this to reproduce the bug


class ReferencedModel(models.Model):
    field = models.FloatField()

    class Meta:
        app_label = 'myapp'


ref = 'ReferencedModel' if SHOULD_I_FAIL else ReferencedModel


class AbstractModel(models.Model):
    # NOTE: only abstract models are affected
    field = models.ForeignKey(ref, on_delete=models.CASCADE)

    class Meta:
        abstract = True
        app_label = 'myapp'


class RealModel(AbstractModel):
    other_field = models.CharField(max_length=100)

    class Meta:
        app_label = 'myapp'


ffield = AbstractModel._meta.get_field('field')
# ValueError: Related model 'ReferencedModel' cannot be resolved
print(ffield.target_field)

[Tim Graham]

Reproduced at 741792961815cf4a95c5ce8ab590dfc7700c6153.

[Alexandr Tatarinov]

I will assume that this is intended behavior. According to #24215, abstract models does not register pending lookups into Apps registry. I have tried to implement it, but found an issue with recursive relations in abstract model - they cannot be resolved but it is valid to have them, because they can be resolved in concrete children classes. So for abstract models lazy-referenced relations should not be resolved. I would not change the triage stage as I am not sure about this.

[Vitalik Verhovodov]

Sounds reasonable, but what if I'm sure that all models are already loaded (e.g. during Command execution)? How can I manually resolve textual model name and target_field?