How to solve You have old files in your logwatch tmpdir (/var/cache/logwatch)

Edit /etc/logwatch/conf/logwatch.conf and override the TmpDir value by changing the default temp directory to /tmp from /var/cache/logwatch

/tmp automatically gets trimmed by most Linux distributions meaning that there won’t be a built up of old log files.

Now delete the old files in /var/cache/logwatch using the command below:

rm -rf /var/cache/logwatch/*