errprintf("cp %s %s\n", src, dst)
	}
	writefile(readfile(src), dst, flag)
}

// dopack copies the package src to dst,
// appending the files listed in extra.
// The archive format is the traditional Unix ar format.
func dopack(dst, src string, extra []string) {
	bdst := bytes.NewBufferString(readfile(src))
	for _, file := range extra {
		b := readfile(file)
		// find last path element for archive member name

		}
	}

	// Look for Godeps.json declaring import path.
	data, _ := os.ReadFile(filepath.Join(dir, "Godeps/Godeps.json"))
	var cfg1 struct{ ImportPath string }
	json.Unmarshal(data, &cfg1)
	if cfg1.ImportPath != "" {
		return cfg1.ImportPath, nil
	}

	// Look for vendor.json declaring import path.
	data, _ = os.ReadFile(filepath.Join(dir, "vendor/vendor.json"))
	var cfg2 struct{ RootPath string }

				if err != nil {
					return err
				}
				dest := filepath.Join("goroot", copydir, srcrel)
				if _, err := os.Stat(dest); err == nil {
					return nil
				}
				data, err := os.ReadFile(path)
				if err != nil {
					return err
				}
				tg.tempFile(dest, string(data))
				if strings.Contains(copydir, filepath.Join("pkg", "tool")) {
					os.Chmod(tg.path(dest), 0777)
				}
				return nil

func (c *runCache) saveOutput(a *work.Action) {
	if c.id1 == (cache.ActionID{}) && c.id2 == (cache.ActionID{}) {
		return
	}

	// See comment about two-level lookup in tryCacheWithID above.
	testlog, err := os.ReadFile(a.Objdir + "testlog.txt")
	if err != nil || !bytes.HasPrefix(testlog, testlogMagic) || testlog[len(testlog)-1] != '\n' {
		if cache.DebugTest {
			if err != nil {

	}

	line, isPrefix, err := l.ReadLine()
	if err != io.EOF {
		t.Errorf("expected EOF from ReadLine, got '%s' %t %s", line, isPrefix, err)
	}
}

func TestReadLineNonNilLineOrError(t *testing.T) {
	r := NewReader(strings.NewReader("line 1\n"))
	for i := 0; i < 2; i++ {
		l, _, err := r.ReadLine()
		if l != nil && err != nil {

	names, err := d.Readdirnames(-1)
	if err != nil {
		return true // conservatively
	}
	for _, name := range names {
		if !strings.HasSuffix(name, "_test.go") {
			continue
		}
		slurp, err := os.ReadFile(filepath.Join(pkgDir, name))
		if err != nil {
			return true // conservatively
		}
		if bytes.Contains(slurp, funcBenchmark) {
			return true
		}
	}
	return false
}

	//           Consider "got X, expected Y" in this case.
	p.errorAt(pos, "syntax error: unexpected "+tok+msg)
}

// tokstring returns the English word for selected punctuation tokens
// for more readable error messages. Use tokstring (not tok.String())
// for user-facing (error) messages; use tok.String() for debugging
// output.
func tokstring(tok token) string {
	switch tok {
	case _Comma:
		return "comma"