added one bug_print ignore in non-deterministic unit test and fixed formatting.

theano/gof/opt.py

@@ -2715,8 +2715,7 @@ def check_stack_trace(f_or_fgraph, ops_to_check='last', bug_print='raise'):
 
     for node in apply_nodes_to_check:
         for output in node.outputs:
-            if (not hasattr(output.tag, 'trace') or
-                not output.tag.trace):
+            if (not hasattr(output.tag, 'trace') or not output.tag.trace):
                 return False
 
     return True

theano/tensor/tests/test_opt.py

@@ -2960,8 +2960,10 @@ def test_local_IncSubtensor_serialize():
 
     # Now test that the stack trace is copied over properly,
     # if we return the gradients. We need to use same mode as before.
+    # the optimizer may delete all instances of AdvancedIncSubtensor
     f = theano.function([i, j, t], dW, mode=mode)
-    assert check_stack_trace(f, ops_to_check=tensor.AdvancedIncSubtensor)
+    assert check_stack_trace(f, ops_to_check=tensor.AdvancedIncSubtensor,
+                             bug_print='ignore')
         
 def test_local_set_to_inc_subtensor():
     v = theano.tensor.fmatrix()