Include an error message hint for inherited ordering

pydantic/_internal/_model_construction.py

@@ -147,6 +147,7 @@ def wrapped_model_post_init(self: BaseModel, __context: Any) -> None:
                         # If that is the case, and a user hits this, I could imagine it being very helpful
                         # to have this extra detail in the reported traceback.
                         error_message += f' (bases={bases})'
+                        error_message += ' Hint: Inherit BaseModel before typing.Generic'
                     raise TypeError(error_message)
 
                 cls.__pydantic_generic_metadata__ = {

tests/test_generics.py

@@ -2022,6 +2022,30 @@ class B(A[T], Generic[S]):
             ...
 
 
+def test_generic_subclass_with_extra_type_with_hint_message():
+    KE = TypeVar('KE')
+    KD = TypeVar('KD')
+    E = TypeVar('E', bound=BaseModel)
+    D = TypeVar('D')
+    Q = TypeVar('Q')
+
+    class BaseGenericClass(Generic[KE, KD, E, D, Q], BaseModel):
+        uid: str
+        name: str
+
+    with pytest.raises(
+        TypeError,
+        match=re.escape(
+            "All parameters must be present on typing.Generic; you should inherit from typing.Generic[~KE, ~KD, ~E, ~D, ~Q] (bases=(<class 'tests.test_generics.test_generic_subclass_with_extra_type_with_hint_message.<locals>.BaseGenericClass'>,)) Hint: Inherit BaseModel before typing.Generic"
+        ),
+    ):
+
+        class ChildGenericClass(
+            BaseGenericClass[KE, KD, E, Dict[str, Any], str],
+        ):
+            ...
+
+
 def test_multi_inheritance_generic_binding():
     T = TypeVar('T')