That seems a frequent e.u.c issue, I reported it to Debian python-apt on https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=800501 and the maintainer replied
"You're probably opened the cache without holding a lock, and an update ran in parallel. That's really the only possible explanation I could think of." ** Changed in: oneconf (Ubuntu) Importance: Medium => High ** Bug watch added: Debian Bug tracker #800501 http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=800501 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to oneconf in Ubuntu. https://bugs.launchpad.net/bugs/1421884 Title: /usr/share/oneconf/oneconf-query:SystemError:/usr/bin/oneconf- query@245:async_update:update:update:compute_local_packagelist:__init__:open Status in oneconf package in Ubuntu: Confirmed Bug description: The Ubuntu Error Tracker has been receiving reports about a problem regarding oneconf. This problem was most recently seen with version 0.3.7, the problem page at https://errors.ubuntu.com/problem/0d46e08ac7a927459ebaf8436dc8de6692abeee5 contains more details. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/oneconf/+bug/1421884/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp