[RFC] log deprecation warnings as a full traceback to .bzr.log.?

[John Arbash Meinel]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Robert Collins wrote:
> https://bugs.launchpad.net/bugs/111045 noted that the user saw an error
> but didn't see anything related to it in .bzr.log.
> 
> -Rob

I think it is tricky to do, since we are letting python handle the
display of deprecation warnings.

But I can certainly see it as useful. Just like we log full tracebacks
for errors that we think are single-line (user).

I'm just not sure how we would do it, since an Exception isn't raised.
(Unless you run with -Werror, in which case we would show a traceback).

Ahh... it looks like you can munge warnings.showwarning().

>>> import warnings
>>> help(warnings)
...
    showwarning(message, category, filename, lineno, file=None)
        Hook to write a warning to a file; replace if you like.


So we could write something like:

import traceback
import warnings


_orig_showwarning = warnings.showwarning


def showwarning_log_traceback(*args, **kwargs):
    formatted_stack = ''.join(traceback.format_stack())
    trace.mutter('Warning encountered:\s%s', formatted_stack)
    _orig_showwarning(*args, **kwargs)


warnings.showwarning = showwarning_log_traceback

John
=:->

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.3 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFGNfWFJdeBCYSNAAMRAsivAJ9nrUL8pTPQ7iHBt/HAva8ACKDT0ACcDgld
blJjvuzuGfrXQ19bLNPXFx4=
=Ml1H
-----END PGP SIGNATURE-----