Sample script:
#!/bin/bash
echo "Hello?"
... (other things)
When run via launchd, it definitely runs (the other things are being done) but nothing shows up in /var/log/system.log. I'm running OS 10.9 Mavericks.
I tried replacing that line with
syslog -s "HELLO?"
but that also shows nothing. I should also add that I'm running the launchd script as a login script but specifying that it run as a daemon user. The user does not have root access. However, I've also tried running syslog as root, and still, nothing shows up in the logs.
This happens on multiple systems.