Comment 22 for bug 1886115

> can you confirm which one you have had to disable the SystemCallFilter?
  Both files are just symlinks to /lib/systemd/system/systemd-resolved.service.

> Also there appear to be a bunch of systemd managed services which have failed to run
  I moved snap related services out of the way recently as it isn't used here. systemd complains, but I didn't observe any other ill effects yet.

> could you perhaps downgrade libseccomp back to the previous version and see if this resolves the issue?
--8<--
$ sudo apt install libseccomp=2.4.1-0ubuntu0.18.04.2
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package libseccomp
tho@deimos:~$ sudo apt install libseccomp2=2.4.1-0ubuntu0.18.04.2
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Version '2.4.1-0ubuntu0.18.04.2' for 'libseccomp2' was not found
-->8--

  I attempted to downgrade earlier, but couldn't readily find that original package. Let me have another look (I might have still the original install medium) ...

> try and capture a more complete stack trace of the crash
  Hmmh? The call stack is fairly shallow here (not untypical for non-recursive applications programmed in C), what do you expect is missing? I saved the original core file, but can produce a new one as you described above later.