Originally Posted By: artie505
It just occurred to me to look in Console, and I found

Code:
10/17/16 7:14:12.424 AM com.apple.xpc.launchd[1]: (com.apple.SafariServices[44416])
Service exited due to signal: Trace/BPT trap: 5

Google isn't the least bit helpful.

FWIW, (and that may not be much!) a "trap" is an externally accessible trigger an author puts in their app, to either "signal" something (like "files were dropped into that folder, you need to process them now") or to kill it. ("ok render engine, we're done with this video, you can quit now") So apps quitting due to a caught signal is often expected behavior. Hitting Ctrl-C while a terminal script is running is an example of a signal that didn't get trapped. The app can elect to ignore most signals that are trying to kill it (by trapping them) also, so they usually "die willingly". Selecting to quit an app in activity monitor sends a signal. Selecting to KILL an app from Force Quit sends a "kill -9", also known as an "uncatchable signal", which cannot be caught with a trap, (isn't that terminology fun?) and will force the app to terminate after the kernel cleans up after it. (kernel having problems doing cleanup is what makes for processes that "refuse to die")

I work for the Department of Redundancy Department