MariaDB cannot start after update: [Warning] Can't create test file /home/mysql/beta.lower-test
<p>I've just updated MariaDB using apt-get dist-upgrade. Now it won't start using <strong>service mysql start</strong> anymore.</p>

<p>I can however, run it as root or do: <strong>sudo -u mysql mysqld_safe</strong> then MariaDB starts up fine. The folder /home/mysql is owned by the mysql user and group.</p>

<p>I've found the error to be thrown in this function:
<a href="https://github.com/MariaDB/server/blob/7ff44b1a832b005264994cbdfc52f93f69b92cdc/sql/mysqld.cc#L9865" rel="noreferrer">https://github.com/MariaDB/server/blob/7ff44b1a832b005264994cbdfc52f93f69b92cdc/sql/mysqld.cc#L9865</a></p>

<p>I can't figure out what to do next. Any pointers?</p>