The [DNSError] type now wraps errors caused by timeouts or cancellation.
For example, `errors.Is(someDNSErr, context.DeadlineExceedeed)`

// Errors returned by Scanner.
var (
	ErrTooLong         = errors.New("bufio.Scanner: token too long")
	ErrNegativeAdvance = errors.New("bufio.Scanner: SplitFunc returns negative advance count")
	ErrAdvanceTooFar   = errors.New("bufio.Scanner: SplitFunc returns advance count beyond input")
	ErrBadReadCount    = errors.New("bufio.Scanner: Read returned impossible count")
)

	offset int
}

func (d *openDir) Close() error               { return nil }
func (d *openDir) Stat() (fs.FileInfo, error) { return d.e.stat() }

func (d *openDir) Read([]byte) (int, error) {
	return 0, &fs.PathError{Op: "read", Path: d.e.name, Err: errors.New("is a directory")}
}

func (d *openDir) ReadDir(count int) ([]fs.DirEntry, error) {
	n := len(d.files) - d.offset
	if count > 0 && n > count {

func addProblem(url, errmsg string) {
	msg := fmt.Sprintf("Error on %s: %s (from %s)", url, errmsg, linkSources[url])
	if *verbose {
		log.Print(msg)
	}
	problems = append(problems, msg)
}

func crawlLoop() {
	for url := range urlq {
		if err := doCrawl(url); err != nil {
			addProblem(url, err.Error())
		}
	}
}

func doCrawl(url string) error {
	defer wg.Done()

			diag = true
			log.Printf(format, args...)
		}
		if *flags.SymABIs {
			ok = parser.ParseSymABIs(buf)
		} else {
			pList := new(obj.Plist)
			pList.Firstpc, ok = parser.Parse()
			// reports errors to parser.Errorf
			if ok {
				obj.Flushplist(ctxt, pList, nil)
			}
		}
		if !ok {
			failedFile = f
			break
		}
	}
	if ok && !*flags.SymABIs {
		ctxt.NumberSyms()

	if err != nil {
		t.Error("unexpected error on ReadRune (2):", err)
	}
	_, err = r.Read(buf)
	if err != nil {
		t.Error("unexpected error on Read (2):", err)
	}
	if r.UnreadRune() == nil {
		t.Error("expected error after Read (2)")
	}
	// Test error after ReadByte.
	_, _, err = r.ReadRune() // reset state
	if err != nil {
		t.Error("unexpected error on ReadRune (2):", err)
	}
	for range buf {

	fw *flate.Writer
}

func (w *pooledFlateWriter) Write(p []byte) (n int, err error) {
	w.mu.Lock()
	defer w.mu.Unlock()
	if w.fw == nil {
		return 0, errors.New("Write after Close")
	}
	return w.fw.Write(p)
}

func (w *pooledFlateWriter) Close() error {
	w.mu.Lock()
	defer w.mu.Unlock()
	var err error
	if w.fw != nil {
		err = w.fw.Close()
		flateWriterPool.Put(w.fw)
		w.fw = nil
	}

			parser.lineNum++
			if !parser.pseudo(test.pseudo, tokenize(test.operands)) {
				t.Fatalf("Wrong pseudo-instruction: %s", test.pseudo)
			}
			errorLine := buf.String()
			if test.expected != errorLine {
				t.Errorf("Unexpected error %q; expected %q", errorLine, test.expected)
			}
			buf.Reset()
		}
	}

var (
	ErrHeader          = errors.New("archive/tar: invalid tar header")
	ErrWriteTooLong    = errors.New("archive/tar: write too long")
	ErrFieldTooLong    = errors.New("archive/tar: header field too long")
	ErrWriteAfterClose = errors.New("archive/tar: write after close")
	ErrInsecurePath    = errors.New("archive/tar: insecure file path")
	errMissData        = errors.New("archive/tar: sparse file references non-existent data")

func (r *Reader) UnreadRune() error {
	if r.i <= 0 {
		return errors.New("bytes.Reader.UnreadRune: at beginning of slice")
	}
	if r.prevRune < 0 {
		return errors.New("bytes.Reader.UnreadRune: previous operation was not ReadRune")
	}
	r.i = int64(r.prevRune)
	r.prevRune = -1
	return nil
}

// Seek implements the [io.Seeker] interface.