Certain MFX-detected errors simply produce an error message. In some of these cases, it may be useful to produce a dump for better diagnosis.
If RC16=ABE is set, a user abend 16 will be produced in case of an error, but no dump will be generated. In such cases, the diagnostic parameter DEBUG may be used to produce a SNAP dump (that is, a dump before any cleanup has taken place). DEBUG will also cause the sort to issue a user abend 16.
In the case of a system abend, a dump will be produced regardless of the parameters that are in effect. Should DEBUG be specified in this case, two dumps may be produced: a SNAP dump and the usual system dump. Both dumps generally have the same content.
In addition to a dump, DEBUG produces a listing of internal variables after each of the main phases, which may be useful to Precisely Support. The listing is produced on the SPYSET data set, if present. If only SYSOUT is present, the listing will not be produced, but the SNAP dump may be produced. To guarantee that both the listing and the dump will be produced, you must supply a SPYSET DD statement in the step. A SYSABEND statement will result in a full system dump, including a dump of the nucleus.
The DEBUG parm may be specified through any of the usual methods: EXEC parmlist, alternate parm facility ($ORTPARM), PARMTABLE, or PARMEXIT.