Failed to copy data from STDIN pipe to temp file with error

Error message

Failed to copy data from STDIN pipe to temp file with error: %w

What it means

After creating the spill temp file, remaining STDIN data is copied into it with io.Copy. If that copy fails (mid-stream write/read error), this error is returned. It means the pipe or the temp filesystem failed while transferring large clipboard data.

Solutions

Verify the upstream pipeline command completes without being killed
Ensure the temp filesystem has space for the full payload
Re-run with a smaller payload to confirm the size threshold is the issue

Defensive patterns

Strategy: retry

Validate before calling

// ensure temp fs has space: check syscall.Statfs on os.TempDir() before the transfer

Try / catch

if err != nil && strings.Contains(err.Error(), "copy data from STDIN") { /* free space / smaller payload, then re-run */ }

Prevention

Ensure temp filesystem capacity exceeds the payload size
Prevent upstream producers from being killed mid-stream

When it happens

Trigger: Piping >2MB where the writer dies mid-copy (EPIPE) or the temp filesystem fills up during io.Copy.

Common situations: Upstream command killed by a signal mid-pipe; tmpfs disk-full while spilling large clipboard payloads.

Related errors

AI-assisted analysis of kovidgoyal/kitty@6d5d0c4406 (2026-08-27). Data as JSON: /api/errors/badffc8fe288ec2a. Report an issue: GitHub.

Appendix: source

Thrown at kittens/clipboard/legacy.go:89

	var stdin_data []byte
	stdin_data, err = read_all_with_max_size(os.Stdin, 2*1024*1024)
	if err == nil {
		os.Stdin.Close()
	} else if err != ErrTooMuchPipedData {
		os.Stdin.Close()
		err = fmt.Errorf("Failed to read from STDIN pipe with error: %w", err)
		return
	}
	if err == ErrTooMuchPipedData {
		tempfile, err = utils.CreateAnonymousTemp("")
		if err != nil {
			return nil, nil, fmt.Errorf("Failed to create a temporary from STDIN pipe with error: %w", err)
		}
		tempfile.Write(stdin_data)
		_, err = io.Copy(tempfile, os.Stdin)
		os.Stdin.Close()
		if err != nil {
			return nil, nil, fmt.Errorf("Failed to copy data from STDIN pipe to temp file with error: %w", err)
		}
		tempfile.Seek(0, io.SeekStart)
		data_src = tempfile
	} else if stdin_data != nil {
		data_src = bytes.NewBuffer(stdin_data)
	}
	return
}

func run_plain_text_loop(opts *Options) (err error) {
	stdin_is_tty := tty.IsTerminal(os.Stdin.Fd())
	var data_src io.Reader
	var tempfile *os.File
	if !stdin_is_tty && !opts.GetClipboard {
		// we dont read STDIN when getting clipboard as it makes it hard to use the kitten in contexts where
		// the user does not control STDIN such as being execed from other programs.
		data_src, tempfile, err = preread_stdin()
		if err != nil {

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