0  0x00007fff87123eb6 in recvfrom ()
   1  0x000000001536d43c in zmq::mailbox_t::recv ()
   2  0x0000000015374e98 in zmq::socket_base_t::process_commands ()
   3  0x000000001537509e in zmq::socket_base_t::recv ()
   4  0x00000000151081e1 in VM::ticker ()
   5  0x000000001510987b in VM::run ()
   6  0x0000000015109ad8 in start_vm ()
   7  0x000000001018e431 in thr_wrapper ()
   8  0x00007fff87119536 in _pthread_start ()
   9  0x00007fff871193e9 in thread_start ()