func cmdBuild(img *jetpack.Image, args []string) error {
if nimg, err := img.Build(flBuildDir, flBuildCp, args); err != nil {
return errors.Trace(err)
} else {
if err := cmdShowImage(nimg); err != nil {
return errors.Trace(err)
}
if SaveID != "" {
return errors.Trace(ioutil.WriteFile(SaveID,
[]byte(nimg.Hash.String()+"\n"), 0644))
}
return nil
}
}
