I tested this today by first restoring the clone file found in the tarball in comment #20 then enabling and installing all the packages in -proposed for Ubuntu 16.04. I then modified DistUpgradeController.py in the dist-upgrader tarball so that -proposed would*n't* be disabled during the upgrade. With all of that I still encountered the following error:
Removing webbrowser-app (0.23+16.04.20161028-0ubuntu2) ... dpkg: cycle found while processing triggers: chain of packages whose triggers are or may be responsible: bamfdaemon -> desktop-file-utils packages' pending triggers which are or may be unresolvable: gnome-menus: /usr/share/applications bamfdaemon: /usr/share/applications libglib2.0-0:amd64: /usr/share/glib-2.0/schemas desktop-file-utils: /usr/share/applications mime-support: /usr/share/applications dpkg: error processing package gnome-menus (--remove): triggers looping, abandoned Processing triggers for desktop-file-utils (0.22-1ubuntu5.2) ... Processing triggers for mime-support (3.59ubuntu1) ... Processing triggers for libglib2.0-0:amd64 (2.48.2-0ubuntu3) ... Errors were encountered while processing: gnome-menus -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-menus in Ubuntu. https://bugs.launchpad.net/bugs/1766890 Title: package gnome-menus 3.13.3-6ubuntu3.1 failed to install/upgrade: triggers looping, abandoned To manage notifications about this bug go to: https://bugs.launchpad.net/oem-priority/+bug/1766890/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
