$server->close throw a error when swoole set dispatch_func

[GDdark]

Error code:

$server = new Swoole\Websocket\Server("0.0.0.0", 9502);

$server->set([
    'dispatch_func' => function ($server, $fd, $type, $data) {
        return 0;
    },
]);

$server->on('open', function($server, $req) {
    $server->close($req->fd);  // bug：trigger a error !!!
});

$server->on('message', function($server, $frame) {
    // nothing
});

$server->on('close', function($server, $fd) {
    echo 'close' . $fd . PHP_EOL; // can not be printed
});

$server->start();

Log：

Swoole Version：v4.5.1