H!, I just found this issue (https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1032240) when browsing the list of release critical issues for Trixie (although it is from 2023 and was open also when Bookworm was released, so not really a Trixie issue).
A variant of it was https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1032047 where the MariaDB service shut down the Akonadi started MariaDB server. It was discussed in Feb-March 2023 in that bug and fixed at the end of March 2023 by making sure the system-wide MariaDB service file does not meddle with the Akonadi started services. As Akonadi automatically starts the service, it should probably also have automation to stop it on behalf of the user? Maybe provide something the MariaDB preinstall should call? There is no option to "stop the upgrade" in Debian. Once a user runs `apt upgrade` it needs to complete, there is no way of stopping in the middle or rolling back automatically. If a single maintainer script emits `exit 1` it will only cause dpkg to fail and get caught in a state where users are unable to install or remove anything. So, repeating, the upgrades need to complete and there is no option to abort them. In Feb 2023 I emphasized the view that the MariaDB maintainer scripts should only do things automatically for stuff that it managed in the first place. Stopping every mysqld/mariadbd service on the system purely by process name would seem overreaching. Akonadi maintainers - please suggest how you want to solve this.
