Hi! I did a bunch of reproducible experiments using Salsa-CI in https://salsa.debian.org/mariadb-team/mariadb-server/-/pipelines/536587 testing:
## upgrade to Bookworm * cacti and Bullseye upgrade - apt install -qq --yes cacti -> - apt full-upgrade -qq --yes * default-mysql-server and Bullseye upgrade - apt install -qq --yes default-mysql-server -> - apt full-upgrade -qq --yes * mariadb-server and Bullseye upgrade - apt install -qq --yes mariadb-server * zoph and Bullseye upgrade - apt install -qq --yes zoph -> - apt full-upgrade -qq --yes * zoph and Bullseye upgrade with mariadb-server explicitly - apt install -qq --yes zoph mariadb-server -> - apt install -qq --yes mariadb-server + apt full-upgrade -qq --yes * zoph with mariadb-server and Bullseye upgrade - apt install -qq --yes zoph mariadb-server -> - apt full-upgrade -qq --yes Only the last scenario failed. This suggests that perhaps users hit this issue only when having indirect dependency on default-mysql-server (via e.g. zoph), and upgrading only it or doing a full-upgrade. ## Recommendation how to avoid this issue I would recommend this as the best way as of today to update MariaDB 10.5.19/20 in Buster to 10.11.3 in Debian 12 "Bookworm": # Ensure Bullseye was running latest of everything, makes upgrade smoother $ sudo apt upgrade --yes # Ensure clean and safe shutdown before doing major version upgrade - this may take several minutes on large and busy database $ sudo systemctl stop mariadb || sudo /etc/init.d/mariadb stop # Enable new release $ sed -i 's/bullseye/bookworm/g' /etc/apt/sources.list $ sudo apt update # Just upgrade MariaDB first so it can be brought back online as fast as possible $ sudo apt install mariadb-server # Then upgrade everything else $ sudo apt full-upgrade ## Recommendation how to recover if suffered this issue If you did not prepare along the lines of above and just upgraded, and if failed with error message: dpkg: mariadb-server-10.5: dependency problems, but removing anyway as you requested: zoph depends on default-mysql-server | virtual-mysql-server; however: Package default-mysql-server is not configured yet. Package virtual-mysql-server is not installed. Package mariadb-server-10.5 which provides virtual-mysql-server is to be removed. (Reading database ... 16559 files and directories currently installed.) Removing mariadb-server-10.5 (1:10.5.19-0+deb11u2) ... Stopping MariaDB database server: mariadbd failed! invoke-rc.d: initscript mariadb, action "stop" failed. dpkg: error processing package mariadb-server-10.5 (--remove): installed mariadb-server-10.5 package pre-removal script subprocess returned error exit status 1 dpkg: too many errors, stopping Errors were encountered while processing: mariadb-server-10.5 Processing was halted because there were too many errors. E: Sub-process /usr/bin/dpkg returned an error code (1) ..in that case the easiest way to recover is simply to manually stop the server and continue upgrade: $ sudo pkill -ef mariadbd || sudo pkill -ef mysqld $ sudo apt --fix-broken install $ sudo apt full-upgrade Workaround suggested to be included in Bookworm release notes at https://salsa.debian.org/ddp-team/release-notes/-/merge_requests/197