Comment 21 for bug 46530

Just uninstalling the offending package should put the system into a usable state again.
Another option mentioned e.g. in http://lists.debian.org/debian-devel/1999/08/msg00852.html is to use the `--force-depends' flag while installing/fixing your dependencies as in:

dpkg --configure --force-depends -a

Note that this may introduce more dependency problems :]