I just created a fresh bionic lxd and installed "mysql-server" on it. There was no such error.
Preparing to unpack .../linux-firmware_1.173.1_all.deb ... Unpacking linux-firmware (1.173.1) over (1.173) ... Setting up mysql-common (5.8+1.0.4) .. update-alternatives: error: alternative link /etc/mysql/my.cnf is already managed by my.cnf.bak dpkg: error processing package mysql-common (--configure): installed mysql-common package post-installation script subprocess returned error exit status 2 I checked your installation log and you seem to have installed, removed, purged, reinstalled, purged again, etc, mysql multiple times. That combined with my simple "apt install mysql-server" above that worked make me believe your system has local modifications that are preventing the installation from continuing. I'm going to mark this bug as incomplete pending fresh information on how to reproduce this problem. ** Changed in: mysql-defaults (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Server, which is subscribed to mysql-defaults in Ubuntu. https://bugs.launchpad.net/bugs/1773835 Title: package mysql-common 5.8+1.0.4 failed to install/upgrade: installed mysql-common package post-installation script subprocess returned error exit status 2 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mysql-defaults/+bug/1773835/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs