The script in /var/lib/mysql-files seems very old;
We do something similar now, but the "install plugin" line was removed, because that line will return an error if the plugin is already installed, aborting the script before it reaches shutdown, thus causing the installation to hang.
If that file is somehow set to be used it could cause a hang, but it would either need to be specified in the config file (which we've never done automatically) or somehow have the filename postinst expects to find (which we generate with mktemp --tmpdir /var/lib/mysql-files).
The script in /var/lib/ mysql-files seems very old;
We do something similar now, but the "install plugin" line was removed, because that line will return an error if the plugin is already installed, aborting the script before it reaches shutdown, thus causing the installation to hang.
If that file is somehow set to be used it could cause a hang, but it would either need to be specified in the config file (which we've never done automatically) or somehow have the filename postinst expects to find (which we generate with mktemp --tmpdir /var/lib/ mysql-files) .
So not entirely sure what's happened here.