See this duplicate: https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/1855259/comments/11. This is likely a bug in fanotify or Sophos, not dpkg.
It would be useful to know whether the original poster (https://launchpad.net/~jsamuel-s) was using Sophos AV or fanotify at the time.
See this duplicate: https:/ /bugs.launchpad .net/ubuntu/ +source/ update- manager/ +bug/1855259/ comments/ 11. This is likely a bug in fanotify or Sophos, not dpkg.
It would be useful to know whether the original poster (https:/ /launchpad. net/~jsamuel- s) was using Sophos AV or fanotify at the time.