skaffold render -p dev --set="foo=bar"
read /Users/REDACTED/tmp/kustomize_example/overlays/prod: is a directory

$ skaffold render -p dev --set="foo=bar"
apiVersion: v1
data:
  foo: bar!
kind: ConfigMap
metadata:
  name: prod-basa
---
apiVersion: v1
kind: Pod
metadata:
  labels:
    app: myapp
  name: prod-myapp-pod
spec:
  containers:
    - image: nginx:123
      name: nginx