Exception causes are being removed.

[loweryjk]

I have code raising an exception from another exception.

try:
    return check_response(response)
except KeyError as exc:
    raise Exception('Failed to fetch the data.') from exc

I then have an exception handler.

@app.exception_handler(Exception)
async def exception(request: Request, exc: Exception):
    logger.info(exc)
    if exc.__cause__ is not None:
        logger.info(exc.__cause__)
    return self._json_response(HTTPStatus.INTERNAL_SERVER_ERROR, exc)

The second log statement never executes.

See this ticket for further details: fastapi/fastapi#2683

[oTree-org]

I think this is the same as this issue: #1114

[JayH5]

Yeah this should be fixed by #1158