--- a/devtools/qunit.py	Thu Jun 25 17:13:33 2015 +0200
+++ b/devtools/qunit.py	Thu Nov 26 11:23:52 2015 +0100
@@ -170,6 +170,7 @@
     def publish(self, rset=None):
         event = self._cw.form['event']
         getattr(self, 'handle_%s' % event)()
+        return b''
 
     def handle_module_start(self):
         self.__class__._current_module_name = self._cw.form.get('name', '')