I implemented this using the function set_exc_info() from the _testcapi

_testcapi is very private :) You should not use anything from there. We have no guarantees for it, ever. This is a module with test utils and test cases.

First: it worked on python 3.9 and 3.10, but it stopped working on python 3.11

Most likely it is related to the new exception features: https://docs.python.org/3/library/sys.html#sys.exception (but, again, we never promised that anything from _testcapi will work for you)

CC @iritkatriel

I don’t think this is a bug report about a private API changing. Rather, it’s a request to expose and support the equivalent functionality in a future release.

Yes, I'm saying that it would be good to add this functionality in a future release. We don't need to fix it in the module _testcapi, we need to move it to the main officially supported part of the standard library.

In 3.11 you can modify the traceback on the "exc_info" exception and it will stick:

>>> def raiseTypeError(): raise TypeError
... 
>>> try: raiseTypeError()
... except Exception as e: te = e
... 
>>> def raiseValueError(): raise ValueError
... 
>>> try: raiseValueError()
... except Exception as e:
...     e.__traceback__ = te.__traceback__
...     raise
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 1, in raiseTypeError
ValueError 

See how raiseTypeError raised a ValueError?

You can also use sys.exception() instead of sys.exc_info().

Marking as pending because I don't think I see a use case for exposing set_exc_info, given my previous comment.

Closing. If you do still have an issue this can't solve, please reopen or create a new issue.