objc:objc-exception-object

(objc:objc-exception-object condition)

The thrown object an objc:objc-exception carries, an objc:objc-object-pointer holding one reference (released when the pointer is collected), or nil when nil was thrown. A reader of a condition of the macOS-only objc package; see the macOS GUI guide.

MY-APP> (defvar *e* (handler-case (invoke (invoke "NSArray" "array") "objectAtIndex:" 5)
                      (objc-exception (e) e)))
*E*
MY-APP> (invoke-into 'string (objc-exception-object *e*) "name")
"NSRangeException"