obnam 0.23 crashes when started without --log option. Here is what it spits out on the console:

user@host:~$ obnam backup ./
CRITICAL:root:Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/cliapp/app.py", line 132, in _run
    self.setup_logging()
  File "/usr/lib/python2.6/dist-packages/cliapp/app.py", line 279, in setup_logging
    handler = logging.NullHandler()
AttributeError: 'module' object has no attribute 'NullHandler'

Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/cliapp/app.py", line 132, in _run
    self.setup_logging()
  File "/usr/lib/python2.6/dist-packages/cliapp/app.py", line 279, in setup_logging
    handler = logging.NullHandler()
AttributeError: 'module' object has no attribute 'NullHandler'

-- weinzwang

This is actually a bug in cliapp 0.22, which switched to using logging.NullHandler. That only exists in Python 2.7, and you're using 2.6. Workaround: obnam --log=/dev/null. I'll release a new cliapp soon, it's already fixed in bzr. --liw

done