Hi! Thanks for reporting https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1151058 and following up on https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1141976.
The regression was in 1:10.11.18+deb12u1 that included upstream commit https://github.com/MariaDB/server/commit/9fa3f51f59f5b7a6d84c68a45e6a6579f55847b3 that lead to Debhelper (version 10) injecting extra lines as listed in https://salsa.debian.org/mariadb-team/mariadb-server/-/merge_requests/171#note_817952. Initially 1:10.11.18-0+deb12u1 was only in bookworm-proposed-updates and wasn't let into Bookworm itself due to the regression. However, once Bookworm went into LTS, all pending proposed updates were released, so unfortunately all users who upgraded .17->.18 potentially hit this. The fix in .19 does not have this regression anymore. Upgrades from .17 to .19 skip this issue. The fix does however not include any workaround to shut down potentially existing socket activated instances. If you want to spend time developing such a fix, you are welcome to do so and submit your contribution in the open source spirit at https://salsa.debian.org/mariadb-team/mariadb-server. Alternatively, if you have a support contract with some provider, you can request them to engineer the fix for you (and potentially also submit it to Debian). For anyone who ran into this issue and wanted to manually fix it, simply run `pgrep -ef mariadbd` and/or `pgrep -ef mysqld` and look at your process listings to see that all instances have shut down. After that you can restart your system or just restart the systemd service to let systemd manage starting the service.
