Added DEBUG_OUTPUT to ERROR, since this is convenient during debugging

library/error/src/error.e

@@ -8,6 +8,11 @@ note
 deferred class
 	ERROR
 
+inherit
+	ANY
+
+	DEBUG_OUTPUT
+
 feature -- Access
 
 	code: INTEGER
@@ -47,6 +52,13 @@ feature -- String representation
 			end
 		end
 
+feature -- Status report
+
+	debug_output: STRING
+		do
+			Result := string_representation.as_string_8
+		end
+
 feature -- Change
 
 	set_parent (a_parent: like parent)