introduced new logging subsystem using bus:

passive listeners can register on the bus
  active listeners wait for signals actively
  multiplexing allows multiple listeners to receive debug signals
  a lot more...

src/charon/sa/ike_sa_id.h

@@ -27,6 +27,10 @@
 
 #include <types.h>
 
+/**
+ * printf() specifier to print a ike_sa_id.
+ */
+#define IKE_SA_ID_PRINTF_SPEC 'J'
 
 typedef struct ike_sa_id_t ike_sa_id_t;