After a brew install, update, prune or some other operation like upgrading macOS, MariaDB is not starting and after looking at its logs I see something like:
mariadb: missing /usr/local/etc/my.cnf.d
A quick fix is to create the directory: mkdir /usr/local/etc/my.cnf.d
, but be aware that this will happen again. I haven't found any fix on this.
This only applies to MariaDB installations trough homebrew