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

vendor/symfony/class-loader/Tests/Fixtures/deps/traits.php

@@ -0,0 +1,37 @@
+<?php
+
+trait TD
+{
+}
+
+trait TZ
+{
+    use TD;
+}
+
+trait TC
+{
+    use TD;
+}
+
+trait TB
+{
+    use TC;
+}
+
+trait TA
+{
+    use TB;
+}
+
+class CTFoo
+{
+    use TA;
+    use TZ;
+}
+
+class CTBar
+{
+    use TZ;
+    use TA;
+}