(gdb) f 6
#6  0x000000000153f997 in mongo::runQuery (txn=0x7f20df4287d0, m=..., q=..., nss=..., curop=..., result=..., fromDBDirectClient=false) at src/mongo/db/query/find.cpp:862
862                 scoped_ptr<PlanStageStats> execStats(exec->getStats());
(gdb) p state
$11 = mongo::PlanExecutor::DEAD

#0  0x00007f210524420b in raise (sig=5) at ../nptl/sysdeps/unix/sysv/linux/pt-raise.c:37
#1  0x00000000018cada4 in mongo::breakpoint () at src/mongo/util/debugger.cpp:63
#2  0x00000000018bfc37 in mongo::invariantFailed (expr=0x1fa763a "!_killed", file=0x1fa7618 "src/mongo/db/exec/cached_plan.cpp", line=79) at src/mongo/util/assert_util.cpp:147
#3  0x00000000013623ba in mongo::CachedPlanStage::isEOF (this=0xa79caa0) at src/mongo/db/exec/cached_plan.cpp:79
#4  0x0000000001362818 in mongo::CachedPlanStage::getStats (this=0xa79caa0) at src/mongo/db/exec/cached_plan.cpp:166
#5  0x0000000001577bd3 in mongo::PlanExecutor::getStats (this=0xe14f2f0) at src/mongo/db/query/plan_executor.cpp:230
#6  0x000000000153f997 in mongo::runQuery (txn=0x7f20df4287d0, m=..., q=..., nss=..., curop=..., result=..., fromDBDirectClient=false) at src/mongo/db/query/find.cpp:862
#7  0x0000000001444304 in mongo::receivedQuery (txn=0x7f20df4287d0, c=..., dbresponse=..., m=..., fromDBDirectClient=false) at src/mongo/db/instance.cpp:220
#8  0x00000000014454ae in mongo::assembleResponse (txn=0x7f20df4287d0, m=..., dbresponse=..., remote=..., fromDBDirectClient=false) at src/mongo/db/instance.cpp:403
#9  0x0000000001142718 in mongo::MyMessageHandler::process (this=0x35680f8, m=..., port=0xa0cdde0, le=0xa92f1d0) at src/mongo/db/db.cpp:206
#10 0x00000000018e8f98 in mongo::PortMessageServer::handleIncomingMsg (arg=0xa0cdde0) at src/mongo/util/net/message_server_port.cpp:229
#11 0x00007f210523c182 in start_thread (arg=0x7f20df429700) at pthread_create.c:312
#12 0x00007f210433d00d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111