only in patch2:
unchanged:
--- a/core/scripts/test-site.php
+++ b/core/scripts/test-site.php
@@ -12,6 +12,8 @@
   return;
 }
 
+require_once __DIR__ . '/../../autoload.php';
+
 // Use the PHPUnit bootstrap to prime an autoloader that works for test classes.
 // Note we have to disable the SYMFONY_DEPRECATIONS_HELPER to ensure deprecation
 // notices are not triggered.