more info into error msg.

theano/gof/link.py

@@ -46,7 +46,7 @@ def raise_with_op(op, exc_info = None):
     except AttributeError:
         trace = ()
     exc_value.__thunk_trace__ = trace
-    exc_value.args = exc_value.args + (op, )
+    exc_value.args = exc_value.args + (op, ) + ('Sequence id of Apply node='+str(op.env.toposort().index(op)),)
     raise exc_type, exc_value, exc_trace