Comment 2 for bug 463296

Most probably a dupe but I'm not sure nor do I remember the number.
Long story short: qbzr tries to save some info relative to the commit you're undoing in the
remote branch.conf file.
bzr doesn't support that yet.

The workaround for you until that's fixed is to use 'bzr uncommit --no-plugins'.

I'll add qbzr to that bug because I'm surprised that leads to a backtrace, a warning that
the commit info can't be saved sounds more appropriate here.