One way to get an error message out of update-manager about this is to remove libgtk2-perl, if it is already installed, and run update-manager via a terminal. When a package like software-properties-gtk is installed you'll see the following message in the terminal:
debconf: unable to initialize frontend: Gnome debconf: (Can't locate Gtk2.pm in @INC (you may need to install the Gtk2 module) (@INC contains: /etc/perl /usr/local/lib/x86_64-linux-gnu/perl/5.24.1 /usr/local/share/perl/5.24.1 /usr/lib/x86_64-linux-gnu/perl5/5.24 /usr/share/perl5 /usr/lib/x86_64-linux-gnu/perl/5.24 /usr/share/perl/5.24 /usr/local/lib/site_perl /usr/lib/x86_64-linux-gnu/perl-base) at /usr/share/perl5/Debconf/FrontEnd/Gnome.pm line 91.) debconf: falling back to frontend: Dialog -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1607929 Title: update-manager: missing dependency on libgtk2-perl for debconf frontend To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/shim-signed/+bug/1607929/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
