Issue #2527710 by Fabianx: Decouple Error testing from running with container builder

core/modules/system/tests/modules/error_service_test/src/ErrorServiceTestServiceProvider.php

@@ -0,0 +1,28 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\error_service_test\ErrorServiceTestServiceProvider.
+ */
+
+namespace Drupal\error_service_test;
+
+use Drupal\Core\DependencyInjection\ContainerBuilder;
+use Drupal\Core\DependencyInjection\ServiceModifierInterface;
+
+class ErrorServiceTestServiceProvider implements ServiceModifierInterface {
+
+  /**
+   * The in-situ container builder.
+   *
+   * @var \Drupal\Core\DependencyInjection\ContainerBuilder
+   */
+  public static $containerBuilder;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function alter(ContainerBuilder $container) {
+    static::$containerBuilder = $container;
+  }
+}

core/modules/system/tests/modules/error_service_test/src/MonkeysInTheControlRoom.php

@@ -44,7 +44,11 @@ class MonkeysInTheControlRoom implements HttpKernelInterface {
       $kernel = \Drupal::service('kernel');
       $kernel->rebuildContainer();
       // 2) Fetch the in-situ container builder.
-      $container = $kernel->getContainer();
+      $container = ErrorServiceTestServiceProvider::$containerBuilder;
+      // Ensure the compiler pass worked.
+      if (!$container) {
+        throw new \Exception('Oh oh, monkeys stole the ServiceProvider.');
+      }
       // Stop the theme manager from being found - and triggering error
       // maintenance mode.
       $container->removeDefinition('theme.manager');