Something is wrong with the behat setup and so step definitions cannot be listed: <b>{$a->errormsg}</b><br/><br/>Please check:<ul>
<li>$CFG->behat_dataroot, $CFG->behat_prefix and $CFG->behat_wwwroot are set in config.php with different values from $CFG->dataroot, $CFG->prefix and $CFG->wwwroot.</li>
<li>You ran "{$a->behatinit}" from your Moodle root directory.</li>
<li>Dependencies are installed in vendor/ and {$a->behatcommand} file has execution permissions.</li></ul>