Fastapi: [QUESTION] How to make Fastapi put the stacktrace in the body when handling 500 error

[allan-simon]

First check

• [x] I used the GitHub search to find a similar issue and didn't find it.
• [x] I searched the FastAPI documentation, with the integrated search.
• [x] I already searched in Google "How to X in FastAPI" and didn't find any information.

Description

During the development cycle, especially when running on a remote machine (QA environment etc.) it's pretty convenient to have the traceback directly in the body of a 500 response so that one does not have to connect to the machine to get the traceback.

Of course it's something that one should opt-in , as you don't want to have that in production

[phy25]

You could start with https://fastapi.tiangolo.com/tutorial/handling-errors/#install-custom-exception-handlers with a call to a function in traceback module.

[allan-simon]

ah yeah right , stupid me, thanks for the pointer, I will try to come up with something and put it here in case somebody wonders the same thing

[allan-simon]

ok I've hacked this and it seems to work pretty well

if DISPLAY_TRACEBACK_ON_500:

    @app.exception_handler(Exception)
    async def debug_exception_handler(request: Request, exc: Exception):
        import traceback

        return Response(
            content="".join(
                traceback.format_exception(
                    etype=type(exc), value=exc, tb=exc.__traceback__
                )
            )
        )

[phy25]

You may want to close the issue if it works for you :)

[allan-simon]

haha sure

[tiangolo]

Thanks for the help here @phy25 ! :cake: :bow:

Thanks @allan-simon for coming back to close it :+1:

[retnikt]

Starlette has a built-in server exception middleware - use FastAPI(debug=True) to enable it

[mhulo]

Starlette has a built-in server exception middleware - use FastAPI(debug=True) to enable it

The fact that you can set debug=true is mentioned in several places, but not where to or how to. I finally saw your reply after 2hrs of googling. Would be great to get this into the fastapi docs.