sympl-backup: `backup2l -r <regexp>` in Buster only restores directories, and no files
From: https://forum.sympl.host/t/problem-restoring-with-backup2l/138/7
In short, the 'extract' functionality is missing from the TAR driver for backup2l, meaning it can do everything apart from actually extract the relevant files.
The files are backed up okay, but the automatic restore functionality is broken.