Comment 10 for bug 1611256

I tested an upgrade from Ubuntu 16.04 to Ubuntu 18.04 today with the packages gconf2, gparted, preload among others installed. The upgrade completed successfully and there were no issues with triggers looping. I believe this is the result of a new version of dpkg which is available in Ubuntu 16.04.

dpkg (1.18.4ubuntu1.6) xenial; urgency=medium

  * Cherry-pick upstream fixes for trigger loops (LP: #1828639)
    - dpkg: Negate tortoise_not_in_hare() function name and return value
    - dpkg: Initialize trigcyclenode's next member once
    - dpkg: Factor trigproc_new_cyclenode() out from check_trigger_cycle()
    - dpkg: Mark the package we are giving up on a trigger cycle as istobe normal
    - dpkg: Switch dependtry from an int to an enum
    - dpkg: Reset progress_bytrigproc once we have injected into the current iteration
    - dpkg: Split trigger processing types into required, try-queued and try-deferred
    - dpkg: Convert one trigger processing required type into the new try-queued
    - dpkg: Move trigproc cycle reset inside try-deferred conditional
    - dpkg: Introduce a new dependency try level for trigger processing
    - dpkg: Introduce a new dependency try level for trigger cycle checks

 -- Julian Andres Klode <email address hidden> Tue, 16 Jul 2019 14:57:11 +0200