slow log cannot be rotated

I've had to enable the slow log on a production server with lots of traffic to identify some issues however it was growing really fast in size.

I decided to add logrotate to compress and rotate the slow log when it exceeded 1G but to my surprise even though it was rotated and the size appeared smaller, the disk space wasn't actually freed until maria db was restarted

It appears that maria db is holding a lock to the file indefinitely for writing without ever releasing the lock thus the operating system can never release the space that was freed from log rotation

There should either be a way to rotate it via settings or allow the operating system to free the space