--- a/stage1_2/iec_flex.ll	Sun Apr 16 08:46:58 2017 +0100
+++ b/stage1_2/iec_flex.ll	Sun Apr 16 09:00:09 2017 +0100
@@ -96,6 +96,11 @@
 %option nounput
 */
 
+/* The '%option debug' makes the generated scanner run in
+ * debug mode.
+%option debug
+ */
+
 /**************************************************/
 /* External Variable and Function declarations... */
 /**************************************************/