Looking at your log, it looks like you made one of the scripts immutable or otherwise blocked write access to it.
You may want to try "sudo chattr -i /etc/init/network- interface/security.conf" to clear that flag, then retry the upgrade. ** Changed in: ifupdown (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1014629 Title: package ifupdown 0.6.8ubuntu29.2 failed to install/upgrade: ErrorMessage: subprocess new pre-installation script returned error exit status 4 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ifupdown/+bug/1014629/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs