The problem is that the old postrm is being called with no conditionality on the actions it takes; its doing a remove/purge all of the time, when infact its being called with 'upgrade' which then fails due to the interim state of files on disk.
I think the right fix is to only perform the steps in the postrm for remove/purge - upgrade can be an no-op as the collect/compress will happen in the postinst. ** Also affects: horizon (Ubuntu Vivid) Importance: Undecided Status: New ** Also affects: horizon (Ubuntu Wily) Importance: Undecided Status: Confirmed ** Changed in: horizon (Ubuntu Vivid) Status: New => Confirmed ** Changed in: horizon (Ubuntu Vivid) Importance: Undecided => High ** Changed in: horizon (Ubuntu Wily) Importance: Undecided => High -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1506826 Title: Upgrade from kilo to liberty fails To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/horizon/+bug/1506826/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs