Summary

To send a custom message for Pydantic errors, we require the error type. Pydantic's error details are lost while building the error message in SignatureModel._build_error_message. If we add the exc dict to this message, it will be propagated to exception handlers

Basic Example

"SignatureModel"
@classmethod
    def _build_error_message(
        cls,
        keys: Sequence[str],
        exc_msg: str,
        connection: ASGIConnection,
        exc: Optional[Dict[str, Any]] = None
    ) -> ErrorMessage:
    ...
    if exc:
        message["exc"] = exc
    ...

Then in an exception handler, Pydantic's error dict can be accessed by:
validation_exception["extra"][0]["exc"]

Drawbacks and Impact

No response

Unresolved questions

Is there a better way to propagate Pydantic's error object to ValidationException received by the handlers?