-Xephyr will open a window where you can inspect the running test. You can run
-the tests without an X session with Xvfb, such as with +xvfb-run
-./complete-run+. This will also speed up the tests significantly especially on
-machines without a powerful video card.
+Xephyr will open a window where you can inspect the running test. By default,
+tests are run under Xvfb.