Puppet

A crontab entry created like so:

cron{ "test":
    command => "/bin/echo > /tmp/puppet.txt",
    special => "reboot",
}

and then changed like so:

cron{ "test":
    command => "/bin/echo > /tmp/puppet.txt",
    minute  => 50
}

will not change, and will show the notice: notice: //Cron[test]/minute: defined ‘minute’ as ‘50’ on every run.