[Python-Dev] sys.last_traceback - annoying pdb behaviour

[Alexander Schremmer]

Hi there,

when I tried to use pdb, I spotted some kind of annoying behaviour of pdb:
for pdb.pm, it still uses sys.last_traceback which is set by code.py

This renders the function unusable in non-interactive contexts ... I suggest
to change pdb.pm to use sys.exc_traceback instead. Any reasons not to do
so?

For Py3k, it might make sense to kill it completly.

Besides that, some other places in the stdlib reference this attr as well:

idle in 5 places
./lib-tk/Tkinter.py:        sys.last_traceback = tb
./traceback.py:    sys.last_value, sys.last_traceback, limit, file)'."""
./traceback.py:    print_exception(sys.last_type, sys.last_value,
sys.last_traceback,
./pdb.py:    post_mortem(sys.last_traceback)
./code.py:        type, value, sys.last_traceback = sys.exc_info()
./code.py:            sys.last_traceback = tb
./dis.py:            tb = sys.last_traceback

Kind regards,
Alexander