Test-infra: Jobs cloning the kubernetes/release repo are failing due to `/home/prow/go/src/k8s.io/release/.git/hooks/post-update.sample': File exists # Error: exit status 128

[yujuhong]

Example: https://storage.googleapis.com/kubernetes-jenkins/logs/ci-kubernetes-coverage-conformance/404/build-log.txt

# FAILED!
# Cloning kubernetes/release at master
$ mkdir -p /home/prow/go/src/k8s.io/release
$ git init
fatal: cannot copy '/usr/share/git-core/templates/hooks/post-update.sample' to '/home/prow/go/src/k8s.io/release/.git/hooks/post-update.sample': File exists
# Error: exit status 128
# FAILED!

/cc @krzyzacy

[krzyzacy]

cc @cjwagner @stevekuznetsov feels like a cloneref thing?

also cc @Katharine @BenTheElder for the coverage job

[yujuhong]

Failing coverage jobs:
https://testgrid.k8s.io/sig-testing-canaries#ci-kubernetes-coverage-conformance
https://testgrid.k8s.io/sig-testing-canaries#ci-kubernetes-coverage-e2e-gci-gce

[BenTheElder]

Those logs don't make any sense... Is it trying to create the repo thrice (!?)

# FAILED!
# Cloning kubernetes/release at master
$ mkdir -p /home/prow/go/src/k8s.io/release
$ git init
fatal: cannot copy '/usr/share/git-core/templates/hooks/post-update.sample' to '/home/prow/go/src/k8s.io/release/.git/hooks/post-update.sample': File exists
# Error: exit status 128
# FAILED!
# Cloning kubernetes/release at master
$ mkdir -p /home/prow/go/src/k8s.io/release
$ git init
fatal: cannot copy '/usr/share/git-core/templates/hooks/post-update.sample' to '/home/prow/go/src/k8s.io/release/.git/hooks/post-update.sample': File exists
# Error: exit status 128
# Cloning kubernetes/release at master
$ mkdir -p /home/prow/go/src/k8s.io/release
$ git init
Initialized empty Git repository in /home/prow/go/src/k8s.io/release/.git/

[yujuhong]

The tests started failing since last night. Not sure what had changed.

[cjwagner]

This coincides with yesterday's Prow bump. There is probably a regression in plank. Looking now.

[cjwagner]

Here is the problem: https://github.com/kubernetes/test-infra/pull/9952#pullrequestreview-173134225

Making a fix PR now.

[yujuhong]

Can we revert this change or get a quick fix? Thanks!