I find debugging monit to be a major pain. Monit\'s shell environment basically has nothing in it (no paths or other environment variables). Also, there are no log file that
By default, monit logs to your system message log and you can check there to see what's happening.
Also, depending on your config, you might be logging to a different place
tail -f /var/log/monit
http://mmonit.com/monit/documentation/monit.html#LOGGING
Assuming defaults (as of whatever old version of monit I'm using), you can tail the logs as such:
CentOS:
tail -f /var/log/messages
Ubuntu:
tail -f /var/log/syslog
Mac OSX
tail -f /var/log/system.log
Windows
Here be Dragons
But there is a neato project I found while searching on how to do this out of morbid curiosity: https://github.com/derFunk/monit-windows-agent