No output, even with `py.test -s`

I found a work-around.

If I these two lines, then the -s option (shortcut for --capture=no) for py.test works.

    def test_when_the_moon_is_in_the_seventh_house(self):
+        import hunter
+        hunter.trace(module_startswith='modlink')
        ...

And I will see the race, and I am happy.

A solution without modifying the source code would be nice.