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

vendor/symfony/process/Tests/NonStopableProcess.php

@@ -0,0 +1,36 @@
+<?php
+
+/**
+ * Runs a PHP script that can be stopped only with a SIGKILL (9) signal for 3 seconds.
+ *
+ * @args duration Run this script with a custom duration
+ *
+ * @example `php NonStopableProcess.php 42` will run the script for 42 seconds
+ */
+function handleSignal($signal)
+{
+    switch ($signal) {
+        case SIGTERM:
+            $name = 'SIGTERM';
+            break;
+        case SIGINT:
+            $name = 'SIGINT';
+            break;
+        default:
+            $name = $signal.' (unknown)';
+            break;
+    }
+
+    echo "received signal $name\n";
+}
+
+declare (ticks = 1);
+pcntl_signal(SIGTERM, 'handleSignal');
+pcntl_signal(SIGINT, 'handleSignal');
+
+$duration = isset($argv[1]) ? (int) $argv[1] : 3;
+$start = microtime(true);
+
+while ($duration > (microtime(true) - $start)) {
+    usleep(1000);
+}