Message 115469 - Python tracker

> Patch looks good. However tests do not pass with -Werror (while test_warnings and others pass).
> 
> 
> Is there a way to catch multiple warnings on a single logical line?

I thought we could beef up the API with additional arguments.
That would be at the expense of removing the "callable" argument (and
mandating the use as a context manager), though, otherwise the signature
gets too complicated.