Comment 5 for bug 1789977

How are your LVM2 volumes configured? Based on that segfault, I would guess that it has something to do with that (and would not necessarily be reproducible if the volume configuration is not similar).

I would have a hard time believing that it has anything to do with our custom Debian packages. However, it might be worth the trouble to try and configure a fresh 16.04 system and upgrading it, then do it again and try upgrading after adding our packages.