if len(paxHdrs) > 0 || isGlobal {
		// Write each record to a buffer.
		var buf strings.Builder
		// Sort keys for deterministic ordering.
		for _, k := range slices.Sorted(maps.Keys(paxHdrs)) {
			rec, err := formatPAXRecord(k, paxHdrs[k])
			if err != nil {
				return err
			}
			buf.WriteString(rec)
		}

		// Write the extended header file.
		var name string
		var flag byte
		if isGlobal {