See https://github.com/facebook/phabricator/issues/487. If an exception is thrown too high in the stack for the main exception handling to deal with it, we currently never report a stack trace. Instead:

• Always report a stack trace to the error log.
• With developer mode, also report a stack trace to the screen.

Added a high-level throw and hit both cases. Got traces in the log and traces-under-developer-mode on screen.