// the package being tested and the source root.
	pkgpath = ""
	for _, element := range strings.Split(finalPkgpath, string(filepath.Separator)) {
		if debug {
			log.Printf("copying %s", pkgpath)
		}
		pkgpath = filepath.Join(pkgpath, element)
		dst := filepath.Join(dstbase, pkgpath)
		src := filepath.Join(cwd, pkgpath)
		if err := copyLocalDir(dst, src); err != nil {
			return "", err
		}
	}