[Pharo-users] What is code 137 / how to gracefully shut down via SIGTERM?

Hi, I had to find out how to automatically deploy the backend written in Pharo, and so far it uses docker-compose stop to stop the instance (and later docker-compose up -d to get everything up again). I noticed the stop phase takes a while and ends with status code 137. I presume it ended forcefully and not gracefully. What is the idiomatic way to wait on SIGTERM and close the process gracefully? Thanks, Herby