The attached log file shows you removing multiple packages which ultimately resulted in the removal of sudo which is not advised.
Removing guitarpro6 (6.1.6) ... Removing lubuntu-desktop (0.59) ... Removing gdebi (0.9.5.5+nmu1) ... Removing gksu (2.0.2-9ubuntu1) ... Removing libgksu2-0 (2.0.13~pre1-6ubuntu7) ... update-alternatives: removing manually selected alternative - switching libgksu-gconf-defaults to auto mode Removing ubuntu-minimal (1.334) ... Removing sudo (1.8.9p5-1ubuntu5) ... You have asked that the sudo package be removed, but no root password has been set. Without sudo, you may not be able to gain administrative privileges. If you would prefer to access the root account with su(1) or by logging in directly, you must set a root password with "sudo passwd". If you have arranged other means to access the root account, and you are sure this is what you want, you may bypass this check by setting an environment variable (export SUDO_FORCE_REMOVE=yes). Refusing to remove sudo. dpkg: error processing package sudo (--remove): subprocess installed pre-removal script returned error exit status 1 ** Changed in: sudo (Ubuntu) Status: Confirmed => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1487208 Title: package sudo 1.8.9p5-1ubuntu5 failed to install/upgrade: subprocess installed pre-removal script returned error exit status 1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/sudo/+bug/1487208/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs