Program received signal SIGSEGV, Segmentation fault.
0x08057eba in luaH_getstr ()
(gdb) backtrace 
#0  0x08057eba in luaH_getstr ()
#1  0x08059c15 in luaV_gettable ()
#2  0x0805022d in lua_getfield ()
#3  0x0804db11 in LuaMUCHandler::handleMUCParticipantPresence ()