Impossible to create with an inverse one-to-one relationship

[Pascal de Sélys]

Hello, I don't know if this is a bug or if it's something wanted. If I create two models .

Work >>>

Application One:

---

class Foo(models.Model):

   foo_bar = models.IntegerField()

   def save(self, *args, **kwargs):
        created = self._state.adding
        super(EqoLevel, self).save(*args, **kwargs)
        if created:
            self.bar_set.create()
            

---

Application Two:

---

class Bar(models.Model):

    foo = models.ForeignKey("app1.Foo", on_delete=CASCADE,primary_key=True)
    foo_bar_2 = models.IntegerField()
          

Not work >>>

Application One:

---

class Foo(models.Model):

   foo_bar = models.IntegerField()

   def save(self, *args, **kwargs):
        created = self._state.adding
        super(EqoLevel, self).save(*args, **kwargs)
        if created:
            self.bar_set.create()
            

---

Application Two:

---

class Bar(models.Model):

    foo = models.OneToOneField("app1.Foo", on_delete=CASCADE)
    foo_bar_2 = models.IntegerField()
          

But if I use a I can't run a one to one creation with an inverse relationship and yet during makemigrations it says (HINT: ForeignKey(unique=True) is usually better served by a OneToOneField.),

Yes but without this function I can't find it. I can also use a signal but I find it a shame to have to create a signal for the simple creation of a one to one relationship that foreign key can provide.
Thank's