Merge pull request #1736 from nouiz/err_msg

theano/configdefaults.py

@@ -259,7 +259,9 @@ AddConfigVar('gpuelemwise.sync',
 
 AddConfigVar('traceback.limit',
              "The number of stack to trace. -1 mean all.",
-             IntParam(5),
+# We default to 6 to be able to know where v1 + v2 is created in the
+# user script. The bigger this number is, the more run time it takes.
+             IntParam(6),
              in_c_key=False)
 
 AddConfigVar('experimental.mrg',

theano/gof/link.py

@@ -56,14 +56,14 @@ sys.excepthook = thunk_hook
 
 
 # TODO: Make this work with linker defined schedule
-def raise_with_op(op, thunk=None, exc_info=None):
+def raise_with_op(node, thunk=None, exc_info=None):
     """
     Re-raise an exception while annotating the exception object with
     debug info.
 
     Parameters
     ----------
-    op : Apply node
+    node : Apply node
         The Apply node object that resulted in the raised exception.
     exc_info : tuple, optional
         A tuple containing the exception type, exception object and
@@ -94,16 +94,16 @@ def raise_with_op(op, thunk=None, exc_info=None):
         # print a simple traceback from KeyboardInterrupt
         raise exc_type, exc_value, exc_trace
     try:
-        trace = op.tag.trace
+        trace = node.tag.trace
     except AttributeError:
         try:
-            trace = op.op.tag.trace
+            trace = node.op.tag.trace
         except AttributeError:
             trace = ()
     exc_value.__thunk_trace__ = trace
-    exc_value.__op_instance__ = op
-    if op in op.fgraph.toposort():
-        exc_value.__applynode_index__ = op.fgraph.toposort().index(op)
+    exc_value.__op_instance__ = node
+    if node in node.fgraph.toposort():
+        exc_value.__applynode_index__ = node.fgraph.toposort().index(node)
     else:
         exc_value.__applynode_index__ = None
 
@@ -112,7 +112,11 @@ def raise_with_op(op, thunk=None, exc_info=None):
     if raise_with_op.print_thunk_trace:
         log_thunk_trace(exc_value)
 
-    detailed_err_msg = "\nApply node that caused the error: " + str(op)
+    hints = []
+    detailed_err_msg = "\nApply node that caused the error: " + str(node)
+
+    types = [getattr(ipt, 'type', 'No type') for ipt in node.inputs]
+    detailed_err_msg += "\nInputs types: %s\n" % types
 
     if thunk is not None:
         if hasattr(thunk, 'inputs'):
@@ -131,26 +135,43 @@ def raise_with_op(op, thunk=None, exc_info=None):
             strides = "So we can't access the strides of inputs values"
             scalar_values = "And can't print its inputs scalar value"
 
-        types = [getattr(ipt, 'type', 'No type')
-                 for ipt in op.inputs]
-        detailed_err_msg += ("\nInputs shapes: %s" % shapes +
+        detailed_err_msg += ("Inputs shapes: %s" % shapes +
                              "\nInputs strides: %s" % strides +
-                             "\nInputs types: %s" % types +
-                             "\nInputs scalar values: %s" % scalar_values)
+                             "\nInputs scalar values: %s\n" % scalar_values)
     else:
-        detailed_err_msg += ("\nUse another linker then the c linker to"
+        hints.append(
+            "HINT: Use another linker then the c linker to"
             " have the inputs shapes and strides printed.")
 
+    # Print node backtrace
+    tr = getattr(node.tag, 'trace', None)
+    if tr:
+        sio = StringIO.StringIO()
+        traceback.print_list(tr, sio)
+        tr = sio.getvalue()
+        detailed_err_msg += "\nBacktrace when the node is created:"
+        detailed_err_msg += str(tr)
+    else:
+        hints.append(
+            "HINT: Re-running with most Theano optimization disabled could"
+            " give you a back-traces when this node was created. This can"
+            " be done with by setting the Theano flags"
+            " optimizer=fast_compile")
+
     if theano.config.exception_verbosity == 'high':
         f = StringIO.StringIO()
-        theano.printing.debugprint(op, file=f, stop_on_name=True,
+        theano.printing.debugprint(node, file=f, stop_on_name=True,
                                    print_type=True)
-        detailed_err_msg += "\nDebugprint of the apply node: \n" + f.getvalue()
+        detailed_err_msg += "\nDebugprint of the apply node: \n"
+        detailed_err_msg += f.getvalue()
+
     else:
-        detailed_err_msg += ("\nUse the Theano flag 'exception_verbosity=high'"
+        hints.append(
+            "HINT: Use the Theano flag 'exception_verbosity=high'"
             " for a debugprint of this apply node.")
 
-    exc_value = exc_type(str(exc_value) + detailed_err_msg)
+    exc_value = exc_type(str(exc_value) + detailed_err_msg +
+                         '\n' + '\n'.join(hints))
     raise exc_type, exc_value, exc_trace
 
 raise_with_op.print_thunk_trace = False

theano/gof/utils.py

@@ -12,7 +12,13 @@ def add_tag_trace(thing):
     limit = config.traceback.limit
     if limit == -1:
         limit = None
-    thing.tag.trace = traceback.extract_stack(limit=limit)[:-1]
+    tr = traceback.extract_stack(limit=limit)[:-1]
+    # Different python version use different sementic for
+    # limit. python 2.7 include the call to extrack_stack. The -1 get
+    # rid of it.  We also want to get rid of the add_tag_trace call.
+    if tr and "add_tag_trace" in tr[-1][-1]:
+        tr = tr[:-1]
+    thing.tag.trace = tr
     return thing