It is possible you will encounter a bug in cpio.
If this happens, we would like to hear about it. As the purpose of bug
reporting is to improve software, please be sure to include maximum
information when reporting a bug. The information needed is:
Send your report to <bug-cpio@gnu.org>. This is a public mailing
list; all correspondence sent to it is archived and is available at
https://lists.gnu.org/archive/html/bug-cpio. Your bug report
will be visible there, too. The list is not limited to bug reports,
in fact it is dedicated to any kind of technical discussions regarding
GNU cpio. If you wish to subscribe to it, visit
https://lists.gnu.org/mailman/listinfo/bug-cpio.