diff --git a/bin/rdfdb b/bin/rdfdb
--- a/bin/rdfdb
+++ b/bin/rdfdb
@@ -435,4 +435,4 @@ if __name__ == "__main__":
 
         ], debug=True, db=db))
     log.info("serving on %s" % port)
-    prof.run(reactor.run, profile=False)
+    prof.run(reactor.run, profile=None)
diff --git a/light9/effecteval/effectloop.py b/light9/effecteval/effectloop.py
--- a/light9/effecteval/effectloop.py
+++ b/light9/effecteval/effectloop.py
@@ -224,6 +224,6 @@ def makeEffectLoop(graph, stats, outputW
     elif outputWhere == 'leds':
         return LedLoop(graph, stats)
     else:
-        raise NotImplementedError
+        raise NotImplementedError("unknown output system %r" % outputWhere)