fault on null zknode value

gozk_fault

getting: /staging/kafka/brokers/topics
unexpected fault address 0xc200200000
fatal error: fault
[signal 0xb code=0x1 addr=0xc200200000 pc=0x42651f]

goroutine 8 [running]:
[fp=0x7fc0e3cf3b18] runtime.throw(0xa6b677)
	/usr/lib64/golang/src/pkg/runtime/panic.c:473 +0x67
[fp=0x7fc0e3cf3b30] runtime.sigpanic()
	/usr/lib64/golang/src/pkg/runtime/os_linux.c:239 +0xe7
[fp=0x7fc0e3cf3b38] runtime.memmove()
	/usr/lib64/golang/src/pkg/runtime/memmove_amd64.s:47 +0x1f
[fp=0x7fc0e3cf3b68] runtime.gostringn(0x7fc0e3cf3b98, 0x7fc0e3bf2010, 0xffffffffffffffff)
	/usr/lib64/golang/src/pkg/runtime/zstring_linux_amd64.c:76 +0x51
[fp=0x7fc0e3cf3b88] launchpad.net/gozk/zookeeper._Cfunc_GoStringN(0x7fc0e3bf2010, 0x7fc0ffffffff, 0x0, 0x0)
	launchpad.net/gozk/zookeeper/_obj/_cgo_defun.c:19 +0x3b
[fp=0x7fc0e3cf3c40] launchpad.net/gozk/zookeeper.(*Conn).Get(0xc200111540, 0xc2001118a4, 0x1d, 0x0, 0x0, ...)
	launchpad.net/gozk/zookeeper/_obj/_cgo_gotypes.go:727 +0x3bd
[fp=0x7fc0e3cf3c90] github.com/youtube/vitess/go/zk.(*ZkConn).Get(0xc200113458, 0xc2001118a4, 0x1d, 0x0, 0x0, ...)
	/home/david/src/hwymen/golang/src/github.com/youtube/vitess/go/zk/zkconn.go:154 +0xb0
[fp=0x7fc0e3cf3d68] main.handle_node(0xc2000e59c0, 0xc2000d4770, 0xc2000c2750)
	/export/sda3/home/david/src/imgix.go/zkweb.go:80 +0xf7
[fp=0x7fc0e3cf3db8] main.handler(0xc2000e59c0, 0xc2000d4770, 0xc2000c2750)
	/export/sda3/home/david/src/imgix.go/zkweb.go:73 +0xec
[fp=0x7fc0e3cf3dd8] net/http.HandlerFunc.ServeHTTP(0x73a618, 0xc2000e59c0, 0xc2000d4770, 0xc2000c2750)
	/usr/lib64/golang/src/pkg/net/http/server.go:1149 +0x3e
[fp=0x7fc0e3cf3e10] net/http.(*ServeMux).ServeHTTP(0xc2000c0510, 0xc2000e59c0, 0xc2000d4770, 0xc2000c2750)
	/usr/lib64/golang/src/pkg/net/http/server.go:1416 +0x11d
[fp=0x7fc0e3cf3e50] net/http.serverHandler.ServeHTTP(0xc2000bdb90, 0xc2000e59c0, 0xc2000d4770, 0xc2000c2750)
	/usr/lib64/golang/src/pkg/net/http/server.go:1517 +0x16c
[fp=0x7fc0e3cf3fb0] net/http.(*conn).serve(0xc2000d2240)
	/usr/lib64/golang/src/pkg/net/http/server.go:1096 +0x765
[fp=0x7fc0e3cf3fb8] runtime.goexit()
	/usr/lib64/golang/src/pkg/runtime/proc.c:1223
created by net/http.(*Server).Serve
	/usr/lib64/golang/src/pkg/net/http/server.go:1564 +0x266

goroutine 1 [IO wait]:
net.runtime_pollWait(0x7fc0e3d9ef00, 0x72, 0x0)
	/usr/lib64/golang/src/pkg/runtime/znetpoll_linux_amd64.c:118 +0x82
net.(*pollDesc).WaitRead(0xc2000d21a0, 0xb, 0xc200111660)
	/usr/lib64/golang/src/pkg/net/fd_poll_runtime.go:75 +0x31
net.(*netFD).accept(0xc2000d2120, 0x73a720, 0x0, 0xc200111660, 0xb, ...)
	/usr/lib64/golang/src/pkg/net/fd_unix.go:385 +0x2c1
net.(*TCPListener).AcceptTCP(0xc200113490, 0x450846, 0x7fc0e3d13e50, 0x450846)
	/usr/lib64/golang/src/pkg/net/tcpsock_posix.go:229 +0x45
net.(*TCPListener).Accept(0xc200113490, 0xc2000dc300, 0xc2001134b8, 0xc2000d2240, 0x0, ...)
	/usr/lib64/golang/src/pkg/net/tcpsock_posix.go:239 +0x25
net/http.(*Server).Serve(0xc2000bdb90, 0xc2000e57c0, 0xc200113490, 0x0, 0x0, ...)
	/usr/lib64/golang/src/pkg/net/http/server.go:1542 +0x85
net/http.(*Server).ListenAndServe(0xc2000bdb90, 0xc2000bdb90, 0x73a618)
	/usr/lib64/golang/src/pkg/net/http/server.go:1532 +0x9e
net/http.ListenAndServe(0x6c4ee0, 0x5, 0x0, 0x0, 0xc200113458, ...)
	/usr/lib64/golang/src/pkg/net/http/server.go:1597 +0x65
main.main()
	/export/sda3/home/david/src/imgix.go/zkweb.go:109 +0xd2

goroutine 2 [syscall]:

goroutine 5 [chan receive]:
github.com/golang/glog.(*loggingT).flushDaemon(0xa81820)
	/home/david/src/hwymen/golang/src/github.com/golang/glog/glog.go:838 +0x4e
created by github.com/golang/glog.init·1
	/home/david/src/hwymen/golang/src/github.com/golang/glog/glog.go:405 +0x274

goroutine 7 [syscall]:
launchpad.net/gozk/zookeeper._Cfunc_wait_for_watch(0x0)
	launchpad.net/gozk/zookeeper/_obj/_cgo_defun.c:474 +0x2f
launchpad.net/gozk/zookeeper._watchLoop()
	launchpad.net/gozk/zookeeper/_obj/_cgo_gotypes.go:1330 +0x1c
created by launchpad.net/gozk/zookeeper.runWatchLoop
	launchpad.net/gozk/zookeeper/_obj/_cgo_gotypes.go:1303 +0x42
exit status 2