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 } }