Dear maintainer, With the latest upload of MariaDB 10.3, --libmysqld-libs is now supported by mysql_config/mariadb_config: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=928230#46
Can you please trigger a rebuild of amarok once mariadb-10.3_1:10.3.15-1 has hit unstable? Please also consider unblocking the package so it can still go back into buster, if possible. Thanks!