return nil
		}

		// Otherwise, copy the bytes.
		src, err := os.Open(srcPath)
		if err != nil {
			return err
		}
		defer src.Close()

		dst, err := os.OpenFile(dstPath, os.O_WRONLY|os.O_CREATE|os.O_EXCL, perm)
		if err != nil {
			return err
		}

		_, err = io.Copy(dst, src)
		if closeErr := dst.Close(); err == nil {
			err = closeErr
		}
		return err
	})

	if len(newID) != len(id) {
		log.Fatalf("%s: build ID length mismatch %q vs %q", file, id, newID)
	}

	if len(matches) == 0 {
		return
	}

	f, err = os.OpenFile(file, os.O_RDWR, 0)
	if err != nil {
		log.Fatal(err)
	}
	if err := buildid.Rewrite(f, matches, newID); err != nil {
		log.Fatal(err)
	}
	if err := f.Close(); err != nil {
		log.Fatal(err)
	}

	// See https://github.com/golang/go/issues/23795 or
	// https://issuetracker.google.com/issues/73230216.
	lockPath := filepath.Join(os.TempDir(), "go_android_exec-adb-lock")
	lock, err := os.OpenFile(lockPath, os.O_CREATE|os.O_RDWR, 0666)
	if err != nil {
		return 0, err
	}
	defer lock.Close()
	if err := syscall.Flock(int(lock.Fd()), syscall.LOCK_EX); err != nil {
		return 0, err
	}

	//
	// The lock file is never deleted, to avoid concurrent locks on distinct
	// files with the same path.
	lockName := filepath.Join(os.TempDir(), "go_ios_exec-"+deviceID+".lock")
	lock, err = os.OpenFile(lockName, os.O_CREATE|os.O_RDONLY, 0666)
	if err != nil {
		return 1, err
	}
	if err := syscall.Flock(int(lock.Fd()), syscall.LOCK_EX); err != nil {
		return 1, err
	}

pkg os, const ModeType FileMode
pkg os, func Chmod(string, FileMode) error
pkg os, func Lstat(string) (FileInfo, error)
pkg os, func Mkdir(string, FileMode) error
pkg os, func MkdirAll(string, FileMode) error
pkg os, func OpenFile(string, int, FileMode) (*File, error)
pkg os, func SameFile(FileInfo, FileInfo) bool
pkg os, func Stat(string) (FileInfo, error)
pkg os, method (*File) Chmod(FileMode) error

pkg os, func Lstat(string) (fs.FileInfo, error)
pkg os, func Mkdir(string, fs.FileMode) error
pkg os, func MkdirAll(string, fs.FileMode) error
pkg os, func MkdirTemp(string, string) (string, error)
pkg os, func OpenFile(string, int, fs.FileMode) (*File, error)
pkg os, func ReadDir(string) ([]fs.DirEntry, error)
pkg os, func ReadFile(string) ([]uint8, error)
pkg os, func SameFile(fs.FileInfo, fs.FileInfo) bool