PR #28040 fixed one instance of this problem, but it looks to me like there are many more. The following files look broken to me: cluster/gce/gci/configure-helper.sh, cluster/gce/trusty/configure-helper.sh, cluster/images/hyperkube/Makefile, cluster/mesos/docker/deploy-dns.sh, and hack/local-up-cluster.sh. Some other files might also be broken too.