the logrotate file assumes that hiawatha is running when the log is rotated.
/usr/bin/killall -HUP hiawatha
killall returns code 1 and therefore the logrotate executable also exits with an error.
With systemd the logrotate.service is marked as failed, which is very annoying to see. ( my opinion
My quick & dirty solution was this:
/usr/bin/pidof hiawatha > /dev/null && /usr/bin/killall -HUP hiawatha
You know what I'm on to and you'll probably find a much better solution for this.
Thanks for your time,