The main mm log only has basic starting messages and the mm stderr log is empty.

pi@raspberrypi:~/.pm2/logs $ grep -i lucy mm-out.log [2020-12-20 23:10:11.606] [LOG] Module helper loaded: Hello-Lucy [2020-12-20 23:10:12.307] [LOG] Connecting socket for: Hello-Lucy [2020-12-20 23:10:12.308] [LOG] Starting module helper: Hello-Lucy [2020-12-20 23:10:18.859] [INFO] Checking git for module: Hello-Lucy pi@raspberrypi:~/.pm2/logs $