chenhg5/cc-connect · error

tar: %w

Error message

tar: %w

What it means

extractFromTarGz wraps errors from tar.Reader.Next() as "tar: %w". The gzip stream opened fine, but reading the tar entries inside it failed partway — the tar payload is corrupt or malformed after the header region.

Source

Thrown at cmd/cc-connect/update.go:335

	if err != nil {
		return "", err
	}
	defer f.Close()

	gz, err := gzip.NewReader(f)
	if err != nil {
		return "", fmt.Errorf("gzip: %w", err)
	}
	defer gz.Close()

	tr := tar.NewReader(gz)
	for {
		hdr, err := tr.Next()
		if err == io.EOF {
			break
		}
		if err != nil {
			return "", fmt.Errorf("tar: %w", err)
		}
		if hdr.Typeflag != tar.TypeReg {
			continue
		}
		if strings.HasPrefix(hdr.Name, "cc-connect") {
			tmp, err := os.CreateTemp("", "cc-connect-update-*")
			if err != nil {
				return "", err
			}
			if _, err := io.Copy(tmp, tr); err != nil {
				tmp.Close()
				os.Remove(tmp.Name())
				return "", fmt.Errorf("extract: %w", err)
			}
			tmp.Close()
			return tmp.Name(), nil
		}
	}

View on GitHub (pinned to 4000b2338a)

Solutions

1. Re-download the archive (delete any cached copy) and retry — truncation is the most common cause
2. Verify the archive integrity locally: `gzip -t file.tar.gz && tar -tf file.tar.gz`
3. Compare the asset checksum with the value published in the release notes
4. If persistent, inspect the release asset itself — it may be corrupted upstream

Example fix

// before
if err != nil {
    return "", fmt.Errorf("tar: %w", err)
}
// after
if err != nil {
    return "", fmt.Errorf("tar: %w (archive truncated or corrupt; re-download)", err)
}

// test archive integrity before extraction:
cmd := exec.Command("sh", "-c", fmt.Sprintf("gzip -t %s && tar -tzf %s >/dev/null", path, path))
if err := cmd.Run(); err != nil {
    return errors.New("archive failed integrity check; re-download")
}

// Go: treat mid-stream tar errors as corrupt-download
if _, err := extractFromTarGz(path); err != nil {
    if strings.Contains(err.Error(), "tar:") {
        os.Remove(path)
        return errors.New("archive corrupt mid-stream; deleted and re-download required")
    }
    return err
}

When it happens

Trigger: tr.Next() returns a non-EOF error while iterating entries: truncated download (valid gzip header, cut-off tar), bit corruption, an asset that is gzip but not tar, or an I/O read error from disk while streaming.

Common situations: Flaky network truncated the download mid-archive; manually edited or re-compressed archive; CDN/cache serving a corrupted asset; filesystem read errors on the temp file.

Understand the failure class

Background: "failed to read file", EACCES, ENOENT and "could not read <path>" errors: when a program can't read a file from disk — this error's family across 49 libraries.

Related errors

• gzip: %w
• extract: %w
• extract binary: %w
• cc-connect binary not found in archive
• missing --url

AI-assisted analysis of chenhg5/cc-connect@4000b2338a (2026-09-06). Data as JSON: /api/errors/f129fbf9262656c1. Report an issue: GitHub.