using the soapclient like this:

    // we fake the soap client to return our prerecorded xml response and have it decoded via the SoapClient
    $client = new class ( __DIR__ . '/StationList.wsdl', ['trace' => true]) extends SoapClient {
        public function __doRequest(string $request, string $location, string $action, int $version, bool $oneWay = false): string
        {
            return \file_get_contents(__DIR__ . '/Result.xml') ?: throw new RuntimeException('missing PointListRequestResult');
        }
    };

    $client->getTheStationListFull();

will cause a segfault, see provided github repository for a small reproducer.

(gdb) bt
#0 call_end_observers (return_value=0x0, execute_data=0x5574df430000) at ./Zend/zend_observer.c:265
#1 zend_observer_fcall_end_all () at ./Zend/zend_observer.c:293
0000002 0x00005574eae024d9 in php_request_shutdown (dummy=dummy@entry=0x0) at ./main/main.c:1849
0000003 0x00005574eaf59ace in do_cli (argc=3, argv=0x5574f7a43520) at ./sapi/cli/php_cli.c:1136
0000004 0x00005574eac959c6 in main (argc=3, argv=0x5574f7a43520) at ./sapi/cli/php_cli.c:1340

full backtrace here: https://github.com/verfriemelt-dot-org/xdebug-soap-segfault/blob/main/backtrace.log