Tell user how to make the stack trace longer

theano/gof/link.py

@@ -169,7 +169,7 @@ def raise_with_op(node, thunk=None, exc_info=None, storage_map=None):
     # Print node backtraces
     tr = getattr(node.outputs[0].tag, 'trace', [])
     if type(tr) is list and len(tr) > 0:
-        detailed_err_msg += "\nBacktrace when the node is created:\n"
+        detailed_err_msg += "\nBacktrace when the node is created(use Theano flag traceback.limit=N to make it longer):\n"
 
         # Print separate message for each element in the list of batcktraces
         sio = StringIO()