ipfs/kubo · error

error opening gzip reader: %w

Error message

error opening gzip reader: %w

What it means

Fired by unpackTgz when gzip.NewReader fails on the opened archive — the file exists but is not valid gzip data (corrupted download, wrong format). It wraps the gzip error and aborts migration binary extraction.

Source

Thrown at repo/fsrepo/migrations/unpack.go:38

	default:
		err = fmt.Errorf("unrecognized archive type: %s", atype)
	}
	if err != nil {
		return err
	}
	return nil
}

func unpackTgz(arcPath, root, name, out string) error {
	fi, err := os.Open(arcPath)
	if err != nil {
		return fmt.Errorf("cannot open archive file: %w", err)
	}
	defer fi.Close()

	gzr, err := gzip.NewReader(fi)
	if err != nil {
		return fmt.Errorf("error opening gzip reader: %w", err)
	}
	defer gzr.Close()

	var bin io.Reader
	tarr := tar.NewReader(gzr)

	lookFor := root + "/" + name
	for {
		th, err := tarr.Next()
		if err != nil {
			if err == io.EOF {
				break
			}
			return fmt.Errorf("cannot read archive: %w", err)
		}

		if th.Name == lookFor {
			bin = tarr

View on GitHub (pinned to 329838acdf)

Solutions

1. Retry to get a fresh download; truncated transfers are the usual cause
2. Check proxy/AV interference that can mangle binary downloads
3. Download the migration archive manually if it persists

When it happens

Trigger: Thrown at repo/fsrepo/migrations/unpack.go:38 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of ipfs/kubo@329838acdf (2026-09-03). Data as JSON: /api/errors/cb1a21bd1f8e4085. Report an issue: GitHub.