@app.post("/param")
        def endpoint(data: ParamModelV1):  # pragma: no cover
            return data


def test_raises_pydantic_v1_model_in_return_type() -> None:
    class ReturnModelV1(BaseModel):
        name: str

    app = FastAPI()

    with pytest.raises(PydanticV1NotSupportedError):

        @app.get("/return")
        def endpoint() -> ReturnModelV1:  # pragma: no cover

        self,
        path: str,
        endpoint: Callable[..., Any],
        *,
        name: Optional[str] = None,
        dependencies: Optional[Sequence[params.Depends]] = None,
        dependency_overrides_provider: Optional[Any] = None,
    ) -> None:
        self.path = path
        self.endpoint = endpoint
        self.name = get_name(endpoint) if name is None else name

    if operation_id in operation_ids:
        message = (
            f"Duplicate Operation ID {operation_id} for function "
            + f"{route.endpoint.__name__}"
        )
        file_name = getattr(route.endpoint, "__globals__", {}).get("__file__")
        if file_name:
            message += f" at {file_name}"
        warnings.warn(message, stacklevel=1)
    operation_ids.add(operation_id)

    def _format_endpoint_context(self) -> str:
        if not (self.endpoint_file and self.endpoint_line and self.endpoint_function):
            if self.endpoint_path:
                return f"\n  Endpoint: {self.endpoint_path}"
            return ""

        context = f'\n  File "{self.endpoint_file}", line {self.endpoint_line}, in {self.endpoint_function}'
        if self.endpoint_path:

## 0.124.0

### Features

* 🚸  Improve tracebacks by adding endpoint metadata. PR [#14306](https://github.com/fastapi/fastapi/pull/14306) by [@savannahostrowski](https://github.com/savannahostrowski).

### Internal