Issue #2421451 by cilefen, dawehner: Drupal needs comments in opcache

core/install.php

@@ -26,6 +26,11 @@
   exit;
 }
 
+if (function_exists('opcache_get_status') && opcache_get_status()['opcache_enabled'] && !ini_get('opcache.save_comments')) {
+  print 'Systems with OPcache installed must have <a href="http://php.net/manual/en/opcache.configuration.php#ini.opcache.save-comments">opcache.save_comments</a> enabled.';
+  exit();
+}
+
 // Start the installer.
 $class_loader = require_once 'autoload.php';
 require_once __DIR__ . '/includes/install.core.inc';