This issue affected me as well, and thanks a lot for a quick work- around. Just in case anyone else is having the additional problems that I had, where apt update wanted to reinstall the unmodified after I applied the workaround above: I needed to do the following in addition:
dpkg --configure -a && apt-mark hold libffi8 This finishes the terminated configuration, and prevents apt from trying to use the repository version. In addition, I decided to subscribe to this ticket so I'll (hopefully) remember to unmark that package once the issue has been fixed. Maybe this is obvious to others, but it wasn't to me. So perhaps this note might be useful to someone else.
