code: func handleLUCIBuildLegacy(c *router.Context, bucket, builder, numberOrId string) error {
  	var address string
  	if strings.HasPrefix(numberOrId, "b") {
  		address = numberOrId[1:]
  	} else {
  		address = fmt.Sprintf("%s/%s/%s", bucket, builder, numberOrId)
  	}
  
  	build, err := buildbucket.GetBuildLegacy(c.Context, address, true)
  	return renderBuildLegacy(c, build, true, err)
  }
docs: // handleLUCIBuildLegacy renders a LUCI build.