I'm also affected on every fresh Debian Jessie system.
The problem is the missing "/usr/sbin/" part before "munin-run" – because the sbin-directory is not in cron's $PATH.
-- With kind regards, Christian Schrötter -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
