Segmentation error in GetGemPortID ()

BBSim throws the following error when num_onus > 1.
 
2019/01/23 14:15:05      ________    _______   ________                 
2019/01/23 14:15:05     / ____   | / ____   | / _____/  _            
2019/01/23 14:15:05    / /___/ / / /__/ / / /____   /_/            
2019/01/23 14:15:05   / _____  | / _____  | /______  | __  __________ 
2019/01/23 14:15:05  / /___/ / / /__/ / _______/ / / / / __  _  / 
2019/01/23 14:15:05 /_______/ /______/ /______/ // // // /_/  
INFO[0000] Setting Log Level  debug                     
DEBU[0000] Logger setup done                             kafkaBroker= topics="[bbsim.log]"
DEBU[0000] New mediator                                  baseport=50080 ip=10.1.50.10 mode=0 onus=1 pon_ports=1 topics="[bbsim.log]"
INFO[0000] OLT ID: 5 was retrieved.                      topics="[bbsim.log]"
DEBU[0000] Start() Start                                 topics="[bbsim.log]"
DEBU[0000] Listening 10.1.50.10:50080 ...                topics="[bbsim.log]"
DEBU[0014] OLT receives GetDeviceInfo()                  topics="[bbsim.log]"
DEBU[0014] OLT receives EnableInd.                       topics="[bbsim.log]"
DEBU[0014] Enable() Start                                topics="[bbsim.log]"
DEBU[0014] activateOLT() Start                           topics="[bbsim.log]"
INFO[0014] OLT BBSIM OLT sent OltInd.                    topics="[bbsim.log]"
INFO[0014] SendIntfInd olt:5 intf:1 (pon)                topics="[bbsim.log]"
INFO[0014] OLT BBSIM OLT sent IntfInd.                   topics="[bbsim.log]"
INFO[0014] SendOperInd olt:5 intf:0 (nni)                topics="[bbsim.log]"
INFO[0014] SendOperInd olt:5 intf:1 (pon)                topics="[bbsim.log]"
INFO[0014] OLT BBSIM OLT sent OperInd.                   topics="[bbsim.log]"
INFO[0014] ONU discovered.                               onu="vendor_id:\"BBSM\" vendor_specific:\"\\000\\005\\001\\000\" " pon_interface=1 topics="[bbsim.log]"
INFO[0014] sendONUDiscInd Onuid                          interfaceId=1 oltId=5 onuId=0 serial_number=BBSM0000010ffffffff topics="[bbsim.log]"
INFO[0014] OLT id:5 sent ONUDiscInd.                     topics="[bbsim.log]"
DEBU[0014] OLT receives ActivateONU()                    topics="[bbsim.log]"
DEBU[0014] All the Onus are Activated.                   topics="[bbsim.log]"
DEBU[0014] ONU State updated to:1                        topics="[bbsim.log]"
DEBU[0014] ONU IntfID: 1 OnuID: 1 activated succesufully.  topics="[bbsim.log]"
DEBU[0014] Received ONU Device &{1 5 1 up vendor_id:"BBSM" vendor_specific:"\000\005\001\000"  1 0xc0000d8c08} Current: 0 Next: 1  topics="[bbsim.log]"
INFO[0015] sendONUInd Onuid                              interfaceId=1 oltId=5 onuId=1 serial_number=BBSM00000100 topics="[bbsim.log]"
INFO[0015] OLT id:5 sent ONUInd.                         topics="[bbsim.log]"
DEBU[0015] activateOLT() Done                            topics="[bbsim.log]"
DEBU[0015] OLT State updated to:1                        topics="[bbsim.log]"
DEBU[0015] StartPktLoops () Start                        topics="[bbsim.log]"
DEBU[0015] SetupVethHandler(sim_uu5_1_1, sim_ud5_1_1) called   topics="[bbsim.log]"
DEBU[0015] Received OLT Device &

{5 1 1    BBSIM OLT 1 up [\{nni 0 up}

{pon 1 up}] 5 0xc0000d8bd0} Current: 0 Next: 1  topics="[bbsim.log]"
INFO[0015] sim_uu5_1_1 & sim_ud5_1_1 was created.        topics="[bbsim.log]"
INFO[0015] sim_uu5_1_1 & sim_ud5_1_1 was up.             topics="[bbsim.log]"
DEBU[0015] Server handle is created for sim_uu5_1_1      topics="[bbsim.log]"
DEBU[0015] SetupVethHandler(sim_nu5, sim_nd5) called     topics="[bbsim.log]"
INFO[0015] sim_nu5 & sim_nd5 was created.                topics="[bbsim.log]"
INFO[0015] sim_nu5 & sim_nd5 was up.                     topics="[bbsim.log]"
DEBU[0015] Server handle is created for sim_nu5          topics="[bbsim.log]"
DEBU[0015] Created vethnames:[sim_uu5_1_1 sim_nu5]       topics="[bbsim.log]"
DEBU[0015] runPacketPktLoops Start                       topics="[bbsim.log]"
DEBU[0015] recvWorker runs. handler: {0 0x7fbf80001440 -10000000 sim_nu5 3598

{0 0} {0 0} 1000 <nil> <nil>}  topics="[bbsim.log]"
DEBU[0015] runOMCIResponder Start                        topics="[bbsim.log]"
DEBU[0015] recvWorker runs. handler: {0 0x7fbf800009f0 -10000000 sim_uu5_1_1 3596 {0 0}

{0 0} 1000 <nil> <nil>}  topics="[bbsim.log]"
DEBU[0015] recv packet from IF: {0 0x7fbf800009f0 -10000000 sim_uu5_1_1 3596

{1 0} {0 0} 1000 0x7fbf80000bf0 0x7fbf80000e40}   topics="[bbsim.log]"
DEBU[0015] recv packet from IF: {0 0x7fbf800009f0 -10000000 sim_uu5_1_1 3596 {1 0}

{0 0} 1000 0x7fbf80000bf0 0x7fbf80000e40}   topics="[bbsim.log]"
DEBU[0015] Received packet from UNI in grpc Server       interfaceId=1 oltId=5 onuId=1 serial_number=BBSM00000100 topics="[bbsim.log]"
2019/01/23 14:15:21 Key for Onu is {1 1}
DEBU[0015] Closed unichannel                             topics="[bbsim.log]"
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x6ce5b0]
 
goroutine 43 [running]:
github.com/opencord/omci-sim.GetGemPortId(0x100000001, 0x1)
        /home/netsia/go/src/github.com/opencord/omci-sim/omci_state.go:53 +0xd0
gerrit.opencord.org/voltha-bbsim/core.getGemPortID(0x100000001, 0xc0002cd680, 0x1, 0x1)
        /home/netsia/go/src/gerrit.opencord.org/voltha-bbsim/core/core_server.go:548 +0x31
gerrit.opencord.org/voltha-bbsim/core.(*Server).runMainPktLoop(0xc0001740c0, 0xbc36c0, 0xc00029b2c0, 0xbc7980, 0xc0000cda40, 0x0, 0x0)
        /home/netsia/go/src/gerrit.opencord.org/voltha-bbsim/core/core_server.go:415 +0xb05
gerrit.opencord.org/voltha-bbsim/core.(*Server).runPktLoops.func2(0x8, 0xb452d0)
        /home/netsia/go/src/gerrit.opencord.org/voltha-bbsim/core/core_server.go:355 +0x4e
golang.org/x/sync/errgroup.(*Group).Go.func1(0xc000268cf0, 0xc000268d80)
        /home/netsia/go/src/golang.org/x/sync/errgroup/errgroup.go:57 +0x57
created by golang.org/x/sync/errgroup.(*Group).Go
        /home/netsia/go/src/golang.org/x/sync/errgroup/errgroup.go:54 +0x66
root@ubuntu5:/home/netsia/go/src/gerrit.opencord.org/voltha-bbsim#