cbindexplan throws panic when run with invalid values

Build : 6.5.0-4691

./cbindexplan -command=retrieve -cluster="<indexerIP>:<port>" -username="<user>" -password="<pwd>" -output=
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x4609a0]

goroutine 1 [running]:
github.com/couchbase/cbauth/metakv.doCallInner(0xc000069fd0, 0xafb2c4, 0x3, 0xb0a17d, 0x19, 0x0, 0x40, 0xc00007ba40, 0x0)
/home/couchbase/jenkins/workspace/couchbase-server-unix/godeps/src/github.com/couchbase/cbauth/metakv/metakv.go:81 +0xa7
github.com/couchbase/cbauth/metakv.doCall(0xc000069fd0, 0xafb2c4, 0x3, 0xb0a17d, 0x19, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
/home/couchbase/jenkins/workspace/couchbase-server-unix/godeps/src/github.com/couchbase/cbauth/metakv/metakv.go:110 +0x86
github.com/couchbase/cbauth/metakv.doJSONCall(0xc000069fd0, 0xafb2c4, 0x3, 0xb0a17d, 0x19, 0x0, 0x9cdd80, 0xc00007ba40, 0xb2274a, 0x57)
/home/couchbase/jenkins/workspace/couchbase-server-unix/godeps/src/github.com/couchbase/cbauth/metakv/metakv.go:121 +0x6a
github.com/couchbase/cbauth/metakv.(*store).get(0xc000069fd0, 0xb0a17d, 0x19, 0xc00035a940, 0x0, 0x0, 0x5, 0x8060104, 0x5, 0xffffffffffffffff)
/home/couchbase/jenkins/workspace/couchbase-server-unix/godeps/src/github.com/couchbase/cbauth/metakv/metakv.go:159 +0xe3
github.com/couchbase/cbauth/metakv.Get(0xb0a17d, 0x19, 0x20, 0x18, 0xa53100, 0xa17c60, 0xc000288fc0, 0x18, 0x18)
/home/couchbase/jenkins/workspace/couchbase-server-unix/godeps/src/github.com/couchbase/cbauth/metakv/metakv.go:319 +0x45
github.com/couchbase/indexing/secondary/common.GetSettingsConfig.func1(0x0, 0x0, 0x0, 0x20, 0xa53100)
/home/couchbase/jenkins/workspace/couchbase-server-unix/goproj/src/github.com/couchbase/indexing/secondary/common/settings.go:35 +0x78
github.com/couchbase/indexing/secondary/common.(*RetryHelper).Run(0xc0000d5a08, 0xc00000d3e0, 0x3)
/home/couchbase/jenkins/workspace/couchbase-server-unix/goproj/src/github.com/couchbase/indexing/secondary/common/retry_helper.go:36 +0x8f
github.com/couchbase/indexing/secondary/common.GetSettingsConfig(0xc000288e40, 0x42e962, 0xc000000008, 0xb2bda0)
/home/couchbase/jenkins/workspace/couchbase-server-unix/goproj/src/github.com/couchbase/indexing/secondary/common/settings.go:47 +0xd4
github.com/couchbase/indexing/secondary/planner.RetrievePlanFromCluster(0x7ffee2ed8682, 0x12, 0x0, 0x0, 0x0, 0x5, 0x203000, 0x0)
/home/couchbase/jenkins/workspace/couchbase-server-unix/goproj/src/github.com/couchbase/indexing/secondary/planner/proxy.go:54 +0x3f
main.main()
goproj/src/github.com/couchbase/indexing/secondary/cmd/cbindexplan/main.go:254 +0x14b8