Improved error message for MPI tasks that have an incorrect task.

src/task.c

@@ -412,8 +412,8 @@ int task_lock(struct task *t) {
         char buff[MPI_MAX_ERROR_STRING];
         int len;
         MPI_Error_string(err, buff, &len);
-        error("Failed to test request on send/recv task (tag=%lld, %s).",
-              t->flags, buff);
+        error("Failed to test request on send/recv task (type=%s/%s tag=%lld, %s).",
+              taskID_names[t->type], subtaskID_names[t->subtype], t->flags, buff);
       }
       return res;
 #else