System Hang Constants
Use one or more of the following constants in the parameter of Setexceptionhangingmask(_:) to specify the types of exceptions that cause the exception to halt execution so a debugger can be attached.
Overview
When exception-handling domains are nested, NSHangOnTopLevelExceptionMask deals with exceptions that would make it to the top two levels of exception handlers. In the main thread of a Cocoa application, the top-level handler is the global NSApplication instance.