istio: Installing from HEAD causing mixer init failing

If i attempt to install istio using HEAD, the mixer fails to init on startup: Error: unknown flag: --zipkinURL

I realize the installation mechanism detailed below isn’t what is recommended in our docs but filing this so we can catch this well prior to release.

repro on GCP:

gcloud container  clusters create "cluster-1" --zone "us-central1-a"   --enable-kubernetes-alpha --num-nodes "3" --network "default" --no-enable-cloud-logging --no-enable-cloud-monitoring --enable-legacy-authorization

then

git clone https://github.com/istio/istio.git
cd istio

kubectl apply -f install/kubernetes/istio.yaml

---

• the mixer pod shows

  mixer:
    Container ID:  docker://48c0fbcf689302790f13f38fa02e9d445d03574bebadd107185032159966905d
    Image:         gcr.io/istio-testing/mixer:5253b6b574a98b209c0ef3d0d6e90c1b8d6a5c2a
    Image ID:      docker-pullable://gcr.io/istio-testing/mixer@sha256:445a7ca236c6f1f4754da1e57379a001f530c4f21dfed7a2f86981774a1d4434
    Ports:         9091/TCP, 9094/TCP, 42422/TCP
    Args:
      --configStoreURL=fs:///etc/opt/mixer/configroot
      --configStore2URL=k8s://
      --configDefaultNamespace=istio-system
      --zipkinURL=http://zipkin:9411/api/v1/spans
      --logtostderr
      -v
      2
    State:          Waiting
      Reason:       CrashLoopBackOff
    Last State:     Terminated
      Reason:       Error
      Exit Code:    255
      Started:      Wed, 29 Nov 2017 18:21:35 -0800
      Finished:     Wed, 29 Nov 2017 18:21:35 -0800
    Ready:          False
    Restart Count:  6
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from istio-mixer-service-account-token-p20b0 (ro)

---

• with logs

mixer	2017-11-30T02:21:35.470851524Z	--clientCertFiles string A set of comma-separated client X509 cert files
mixer	2017-11-30T02:21:35.470849136Z	--apiWorkerPoolSize int Max number of goroutines in the API worker pool (default 1024)
mixer	2017-11-30T02:21:35.470845065Z	--adapterWorkerPoolSize int Max number of goroutines in the adapter worker pool (default 1024)
mixer	2017-11-30T02:21:35.470842895Z	Flags:
mixer	2017-11-30T02:21:35.470840715Z	
mixer	2017-11-30T02:21:35.470838052Z	mixs server [flags]
mixer	2017-11-30T02:21:35.470825846Z	Usage:
mixer	2017-11-30T02:21:35.470038740Z	Error: unknown flag: --zipkinURL

/cc @selmanj