If an exclude regexp has a syntax error, the error message is awful:
> peter@dewsbx07:/media/GreenDrive/Backups$ obnam backup $HOME
> Traceback (most recent call last):
> File "/usr/lib/python2.6/dist-packages/cliapp/app.py", line 141, in _run
> self.process_args(args)
> File "/usr/lib/python2.6/dist-packages/obnamlib/app.py", line 123, in
> process_args
> cliapp.Application.process_args(self, args)
> File "/usr/lib/python2.6/dist-packages/cliapp/app.py", line 316, in
> process_args
> method(args[1:])
> File "/usr/lib/python2.6/dist-packages/obnamlib/plugins/backup_plugin.py",
> line 95, in backup
> self.compile_exclusion_patterns()
> File "/usr/lib/python2.6/dist-packages/obnamlib/plugins/backup_plugin.py",
> line 136, in compile_exclusion_patterns
> for x in self.app.settings['exclude']]
> File "/usr/lib/python2.6/re.py", line 190, in compile
> return _compile(pattern, flags)
> File "/usr/lib/python2.6/re.py", line 245, in _compile
> raise error, v # invalid expression
> error: nothing to repeat
--liw