Reference ticket in the last KnownFailure message

theano/tests/test_tutorial.py

@@ -166,8 +166,11 @@ class T_extending(unittest.TestCase):
                             fn = lambda x, y: x / y)
 
 
-    @dec.knownfailureif(isinstance(theano.compile.mode.get_default_mode(),theano.compile.debugmode.DebugMode),
-                        "This test fail in DEBUG_MODE but this don't make theano generate some bad code. It is a trouble with DEBUG_MODE")
+    @dec.knownfailureif(
+            isinstance(theano.compile.mode.get_default_mode(),
+                theano.compile.debugmode.DebugMode),
+            ("This test fails in DEBUG_MODE, but the generated code is OK. "
+             "It is actually a problem of DEBUG_MODE, see #625"))
     def test_extending_2(self):
         '''
          This test fails in DebugMode for the same reasons the test in