Library /sys$common/syshlp/dbg$help.hlb DEBUG, SET, TRACE, Qualifiers, /EXCEPTION  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Causes the debugger to trace every exception that is signaled.
    The trace action occurs before any application-declared exception
    handlers are invoked.

    As a result of a SET TRACE/EXCEPTION command, whenever your
    program generates an exception, the debugger reports the
    exception and resignals the exception, thus allowing any
    application-declared exception handler to execute.