case allowedFormats.has(FormatGNU):
		tw.err = tw.writeGNUHeader(&tw.hdr)
		return tw.err
	default:
		return err // Non-fatal error
	}
}

func (tw *Writer) writeUSTARHeader(hdr *Header) error {
	// Check if we can use USTAR prefix/suffix splitting.
	var namePrefix string
	if prefix, suffix, ok := splitUSTARPath(hdr.Name); ok {
		namePrefix, hdr.Name = prefix, suffix
	}

	// Pack the main header.
	var f formatter

		}
	}
	end := []byte("END\n")
	_, err = f.Write(end)
	if err != nil {
		t.Fatal("write end:", err)
	}
	if err := w.Close(); err != nil {
		t.Fatal(err)
	}

	// read back zip file and check that we get to the end of it
	r, err := NewReader(buf, buf.Size())
	if err != nil {
		t.Fatal("reader:", err)
	}
	f0 := r.File[0]
	rc, err := f0.Open()
	if err != nil {
		t.Fatal("opening:", err)
	}

func (c *countdown) split(data []byte, atEOF bool) (advance int, token []byte, err error) {
	if *c > 0 {
		*c--
		return 1, data[:1], nil
	}
	return 0, nil, nil
}

// Check that the looping-at-EOF check doesn't trigger for merely empty tokens.
func TestEmptyLinesOK(t *testing.T) {
	c := countdown(10000)
	s := NewScanner(strings.NewReader(strings.Repeat("\n", 10000)))
	s.Split(c.split)
	for s.Scan() {

		hdr, rawHdr, err := tr.readHeader()
		if err != nil {
			return nil, err
		}
		if err := tr.handleRegularFile(hdr); err != nil {
			return nil, err
		}
		format.mayOnlyBe(hdr.Format)

		// Check for PAX/GNU special headers and files.
		switch hdr.Typeflag {
		case TypeXHeader, TypeXGlobalHeader:
			format.mayOnlyBe(FormatPAX)
			paxHdrs, err = parsePAX(tr)
			if err != nil {
				return nil, err
			}

		}
		files = append(files, f)
	}

	// Type-check package files.
	var sizes types.Sizes
	if w.context != nil {
		sizes = types.SizesFor(w.context.Compiler, w.context.GOARCH)
	}
	conf := types.Config{
		IgnoreFuncBodies: true,
		FakeImportC:      true,
		Importer:         w,
		Sizes:            sizes,
	}
	tpkg, err := conf.Check(name, fset, files, nil)
	if err != nil {
		ctxt := "<no context>"

	if err == ErrBufferFull {
		// Handle the case where "\r\n" straddles the buffer.
		if len(line) > 0 && line[len(line)-1] == '\r' {
			// Put the '\r' back on buf and drop it from line.
			// Let the next call to ReadLine check for "\r\n".
			if b.r == 0 {
				// should be unreachable
				panic("bufio: tried to rewind past start of buffer")
			}
			b.r--
			line = line[:len(line)-1]
		}
		return line, true, nil
	}

	statPath := filepath.Join(os.TempDir(), "go_android_exec-adb-sync-status")
	stat, err := os.OpenFile(statPath, os.O_CREATE|os.O_RDWR, 0666)
	if err != nil {
		return err
	}
	defer stat.Close()
	// Serialize check and copying.
	if err := syscall.Flock(int(stat.Fd()), syscall.LOCK_EX); err != nil {
		return err
	}
	s, err := io.ReadAll(stat)
	if err != nil {
		return err
	}
	if string(s) == goVersion {

	return nil
}

// mountDevImage ensures a developer image is mounted on the device.
// The image contains the device lldb server for idevicedebugserverproxy
// to connect to.
func mountDevImage() error {
	// Check for existing mount.
	cmd := idevCmd(exec.Command("ideviceimagemounter", "-l", "-x"))
	out, err := cmd.CombinedOutput()
	if err != nil {
		os.Stderr.Write(out)
		return fmt.Errorf("ideviceimagemounter: %v", err)
	}

			// spurious blank caused by Split on "\n"
			output = output[1:]
			continue
		}
		t.Errorf("unexpected output: %q", output[0])
		output = output[1:]
	}

	// Checked printing.
	// Now check machine code layout.

	top := pList.Firstpc
	var text *obj.LSym
	ok = true
	ctxt.DiagFunc = func(format string, args ...interface{}) {
		t.Errorf(format, args...)
		ok = false
	}