Added comments of why we have the errors

theano/sandbox/scan_module/tests/test_scan.py

@@ -466,6 +466,10 @@ class TestScan(unittest.TestCase):
 
 
     def test002_generator_one_scalar_output(self):
+        # The test fails, because the work in progress ScanOp always works in
+        # place (even when told not to by DebugMode). As this op will change
+        # soon, and it is in the sandbox and not for user consumption, the
+        # error is marked as KnownFailure
         raise KnownFailureTest
         def f_pow2(x_tm1):
             return 2 * x_tm1
@@ -497,6 +501,10 @@ class TestScan(unittest.TestCase):
     # simple rnn, one input, one state, weights for each; input/state
     # are vectors, weights are scalars
     def test003_one_sequence_one_output_and_weights(self):
+        # The test fails, because the work in progress ScanOp always works in
+        # place (even when told not to by DebugMode). As this op will change
+        # soon, and it is in the sandbox and not for user consumption, the
+        # error is marked as KnownFailure
         raise KnownFailureTest
         def f_rnn(u_t, x_tm1, W_in, W):
             return u_t * W_in + x_tm1 * W