#5227: note that Py_Main doesnt return on SystemExit.

Doc/c-api/veryhigh.rst

@@ -36,6 +36,10 @@ the same library that the Python runtime is using.
    interpreter exits due to an exception, or ``2`` if the parameter list does not
    represent a valid Python command line.
 
+   Note that if an otherwise unhandled :exc:`SystemError` is raised, this
+   function will not return ``1``, but exit the process, as long as
+   ``Py_InspectFlag`` is not set.
+
 
 .. cfunction:: int PyRun_AnyFile(FILE *fp, const char *filename)