For the records of this bug report and people following it, there are a lot of discussions going on in both https://github.com/perl5-dbi/DBD-mysql/issues/275 and https://github.com/MariaDB/mariadb-connector-c/pull/95
I will now import MariaDB 10.3.12 into https://salsa.debian.org/mariadb-team/mariadb-10.3 but postpone uploading it for now in case the issues above might produce something that we can backport and patch upon the mariadb-10.3 packaging in Debian to help fix the issue in Debian. Personally I cannot follow all the details in the Github issues above, so please let me know if something actionable on my side emerges (e.g. patches as mentioned).
