jeessy2/ddns-go · error

%w tar.gz 文件: %s

Error message

%w tar.gz 文件: %s

What it means

untar first wraps the source in gzip.NewReader; if the stream is not valid gzip data, it returns errCannotDecompressFile wrapped with this message and the gzip error. It signals the downloaded .tar.gz artifact is not actually gzip-compressed.

Source

Thrown at util/update/decompress.go:67

	z, err := zip.NewReader(r, r.Size())
	if err != nil {
		return nil, fmt.Errorf("%w zip 文件: %s", errCannotDecompressFile, err)
	}

	for _, file := range z.File {
		_, name := filepath.Split(file.Name)
		if !file.FileInfo().IsDir() && matchExecutableName(cmd, name) {
			return file.Open()
		}
	}

	return nil, fmt.Errorf("在 zip 文件中%w：%q", errExecutableNotFoundInArchive, cmd)
}

func untar(src io.Reader, cmd string) (io.Reader, error) {
	gz, err := gzip.NewReader(src)
	if err != nil {
		return nil, fmt.Errorf("%w tar.gz 文件: %s", errCannotDecompressFile, err)
	}

	t := tar.NewReader(gz)
	for {
		h, err := t.Next()
		if errors.Is(err, io.EOF) {
			break
		}
		if err != nil {
			return nil, fmt.Errorf("%w tar.gz 文件：%s", errCannotDecompressFile, err)
		}
		_, name := filepath.Split(h.Name)
		if matchExecutableName(cmd, name) {
			return t, nil
		}
	}
	return nil, fmt.Errorf("在 tar.gz 文件中%w：%q", errExecutableNotFoundInArchive, cmd)
}

View on GitHub (pinned to 5874c2e666)

Solutions

1. Verify the downloaded file starts with the gzip magic bytes (1f 8b) and is a real .tar.gz
2. Confirm the release URL serves the actual tar.gz asset, not an error page
3. Re-download the asset; use errors.Is(err, errCannotDecompressFile) to identify this family

// Check gzip magic bytes before untarring
head := make([]byte, 2)
if n, _ := io.ReadFull(src, head); n < 2 || head[0] != 0x1f || head[1] != 0x8b {
    return fmt.Errorf("not gzip data")
}

r, err := untar(src, cmd)
if err != nil {
    if errors.Is(err, errCannotDecompressFile) {
        log.Errorf("downloaded artifact is not valid tar.gz: %v", err)
        return errCorruptAsset
    }
    return err
}

When it happens

Trigger: Self-update downloads a .tar.gz asset whose bytes fail gzip.NewReader — server returned an HTML/text error page, the file is uncompressed tar, or the download was truncated/corrupted.

Common situations: Release URL pointing at an error page or wrong artifact; proxy stripping/altering content-encoding; partial download of a large tarball.

Related errors

• %w tar.gz 文件：%s
• %w zip 文件: %s
• %w zip 文件: %v
• 在 tar.gz 文件中%w：%q

AI-assisted analysis of jeessy2/ddns-go@5874c2e666 (2026-09-03). Data as JSON: /api/errors/16c07ef1df930970. Report an issue: GitHub.