Index: channels/chan_sip.c
===================================================================
--- channels/chan_sip.c (revision 32456)
+++ channels/chan_sip.c (working copy)
@@ -13041,6 +13041,10 @@
                        ast_log(LOG_ERROR, "We could NOT get the channel lock for %s! \n", p->owner->name);
                        ast_log(LOG_ERROR, "SIP MESSAGE JUST IGNORED: %s \n", req.data);
                        ast_log(LOG_ERROR, "BAD! BAD! BAD!\n");
+#ifdef DEBUG_THREADS
+                       ast_log(LOG_ERROR, "Channel '%s' locked by %s on line %d of %s.\n",
+                               p->owner->name, p->owner->lock.func[0], p->owner->lock.lineno[0], p->owner->lock.file[0]);
+#endif
                        return 1;
                }
                p->recv = sin;