  
              # Accessing the manager on a swappable model with an
              # explicit manager should raise an attribute error with a
              # helpful message
              try:
                  SwappableModel.objects.all()
                  self.fail('Should raise an AttributeError')
              except AttributeError as e:
                  self.assertEqual(str(e), "Manager isn't available; SwappableModel has been swapped for 'managers_regress.Parent'")
  
 
</s>
            msg = (
                "Manager isn't available; 'managers_regress.SwappableModel' "
                "has been swapped for 'managers_regress.Parent'"
            )
            with self.assertRaisesMessage(AttributeError, msg):
  
              # Accessing the manager on a swappable model with an
              # explicit manager should raise an attribute error with a
              # helpful message
            msg = (
                "Manager isn't available; 'managers_regress.SwappableModel' "
                "has been swapped for 'managers_regress.Parent'"
            )
            with self.assertRaisesMessage(AttributeError, msg):
                  SwappableModel.objects.all()
                  self.fail('Should raise an AttributeError')
              except AttributeError as e:
                  self.assertEqual(str(e), "Manager isn't available; SwappableModel has been swapped for 'managers_regress.Parent'")
  
keep keep keep keep replace keep keep keep keep keep
 Fixed #25054 -- Added app_label to swapped model AttributeError
tests/managers_regress/tests.py