I have found some additional information on how this bug would be reproduced, let me explain:
If you visit this URL: http://cdimage.ubuntu.com/ubuntu- gnome/releases/15.04/ , there are four alpha/beta releases of 15.04 in that directory: alpha-1, alpha-2, beta-1 and beta-2. Now check the manifest file for alpha-1, alpha-2 and/or beta-1 (but not beta-2), for example: http://cdimage.ubuntu.com/ubuntu-gnome/releases/15.04/beta-1/ubuntu-gnome-15.04-beta1-desktop-amd64.manifest You will see that these packages related to systemd and upstart were installed by default: systemd 219-3ubuntu1 systemd-shim 9-1 upstart 1.13.2-0ubuntu7 upstart-bin 1.13.2-0ubuntu7 Notice that the systemd-sysv package is NOT installed by default in the manifest file? This means the binaries such as /sbin/init and /sbin/shutdown are only provided by the "upstart" package. Now, in the latest version of upstart package, these binaries were moved to upstart-sysv and are no longer contained in the upstart package itself. To sum it up, if you start with an alpha-1, alpha-2 and/or beta-1 build of Ubuntu 15.04, and from there, attempt to do a "apt-get update; apt- get dist-upgrade" (or "aptitude update; aptitude upgrade"), it will cause the system to lose those essential binaries and can no longer shutdown/reboot. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1436691 Title: Essential files are missing To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/init-system-helpers/+bug/1436691/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
