php-8.0.30-src/ext/sockets/tests/ipv6_skipif.inc

<?php
if (getenv("CI_NO_IPV6") || !defined("AF_INET6")) {
    die('skip no IPv6 support');
}
if (@stream_socket_client('udp://[::1]:8888') === false)
    die('skip no IPv6 support');