(gdb) bt 1
#0  _Chain_Append_unprotected (the_message_queue=0x408da6bc,
    the_message=0x408dfe30, submit_type=2147483647)
    at ../../cpukit/../../../milkymist/lib/include/rtems/score/chain.inl:443
(More stack frames follow...)
(gdb) p ((CORE_message_queue_Control *) 0x408da6bc)->Pending_messages
$12 = {first = 0x408dfe18, permanent_null = 0x0, last = 0x408dfe18}