When use ks generate

$ ks generate --help
...
Global Flags:
  -v, --verbose count[=-1]   Increase verbosity. May be given multiple times.

if use ks generate with --verbose(or -v), we meet error msg

$ ks generate deployed-service guestbook-ui   \
--image gcr.io/heptio-images/ks-guestbook-demo:0.1  \
--type ClusterIP \
--verbose=-1

unknown flag: --verbose
Usage of prototype-flags:
--containerPort string Container port for service to target. (default "80")
--image string Container image to deploy
--module string Component module
--name string Name of the service and deployment resources
--replicas string Number of replicas (default "1")
--servicePort string Port for the service to expose. (default "80")
--type string Type of service to expose (default "ClusterIP")
--values-file string Prototype values file (file returns a Jsonnet object)
ERROR parse preview args: unknown flag: --verbose

Actually, present ks generate command doesn't send any debug msg, however verbose flag is gobal option, then we could use it in any command.

then, I added verbose to prototype-flags.