Update to drupal 8.0.0-rc1. For more information, see https://www.drupal.org/node/2582663

vendor/symfony/debug/Exception/ContextErrorException.php

@@ -0,0 +1,36 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Debug\Exception;
+
+/**
+ * Error Exception with Variable Context.
+ *
+ * @author Christian Sciberras <uuf6429@gmail.com>
+ */
+class ContextErrorException extends \ErrorException
+{
+    private $context = array();
+
+    public function __construct($message, $code, $severity, $filename, $lineno, $context = array())
+    {
+        parent::__construct($message, $code, $severity, $filename, $lineno);
+        $this->context = $context;
+    }
+
+    /**
+     * @return array Array of variables that existed when the exception occurred
+     */
+    public function getContext()
+    {
+        return $this->context;
+    }
+}