cmd/root.go
func defaultNamespace(c clientcmd.ClientConfig) (string, error) {
	if overrides.Context.Namespace != "" {
		return overrides.Context.Namespace, nil
	}
	ns, _, err := c.Namespace()
	return ns, err
}
func defaultNamespace(c clientcmd.ClientConfig) (string, error) {
	if overrides.Context.Namespace != "" {
		return overrides.Context.Namespace, nil
	}
	ns, _, err := c.Namespace()
	return ns, err
}
// clientConfig.Namespace() is broken in client-go 3.0:
// namespace in config erroneously overrides explicit --namespace