edit error message

django_mongodb_backend/fields/embedded_model.py

@@ -24,7 +24,9 @@ def check(self, **kwargs):
             if field.remote_field:
                 errors.append(
                     checks.Error(
-                        "Embedded models cannot have relational fields.",
+                        "Embedded models cannot have relational fields "
+                        f"({self.embedded_model().__class__.__name__}.{field.name} "
+                        f"is a {field.__class__.__name__}).",
                         obj=self,
                         id="django_mongodb.embedded_model.E001",
                     )
@@ -46,9 +48,7 @@ def get_internal_type(self):
     def _set_model(self, model):
         """
         Resolve embedded model class once the field knows the model it belongs
-        to.
-
-        If __init__()'s embedded_model argument is a string, resolve it to the
+        to. If __init__()'s embedded_model argument is a string, resolve it to the
         corresponding model class, similar to relation fields.
         """
         self._model = model

django_mongodb_backend/schema.py

@@ -35,7 +35,7 @@ def _create_model_indexes(self, model, column_prefix="", parent_model=None):
         Create all indexes (field indexes & uniques, Meta.index_together,
         Meta.unique_together, Meta.constraints, Meta.indexes) for the model.
 
-        If this is a recursive call to due to an embedded model, `column_prefix`
+        If this is a recursive call due to an embedded model, `column_prefix`
         tracks the path that must be prepended to the index's column, and
         `parent_model` tracks the collection to add the index/constraint to.
         """

tests/model_fields_/test_embedded_model.py

@@ -135,4 +135,6 @@ class MyModel(models.Model):
         # The inner CharField has a non-positive max_length.
         self.assertEqual(errors[0].id, "django_mongodb.embedded_model.E001")
         msg = errors[0].msg
-        self.assertEqual(msg, "Embedded models cannot have relational fields.")
+        self.assertEqual(
+            msg, "Embedded models cannot have relational fields (Target.key is a ForeignKey)."
+        )