Catches the exception from pickle.whichmodule()

cloudpickle/cloudpickle.py

@@ -310,7 +310,12 @@ def save_function(self, obj, name=None):
 
         if name is None:
             name = obj.__name__
-        modname = pickle.whichmodule(obj, name)
+        try:
+            # whichmodule() could fail, see
+            # https://bitbucket.org/gutworth/six/issues/63/importing-six-breaks-pickling
+            modname = pickle.whichmodule(obj, name)
+        except Exception:
+            modname = None
         # print('which gives %s %s %s' % (modname, obj, name))
         try:
             themodule = sys.modules[modname]
@@ -594,7 +599,12 @@ def save_global(self, obj, name=None, pack=struct.pack):
 
         modname = getattr(obj, "__module__", None)
         if modname is None:
-            modname = pickle.whichmodule(obj, name)
+            try:
+                # whichmodule() could fail, see
+                # https://bitbucket.org/gutworth/six/issues/63/importing-six-breaks-pickling
+                modname = pickle.whichmodule(obj, name)
+            except Exception:
+                modname = '__main__'
 
         if modname == '__main__':
             themodule = None

tests/cloudpickle_test.py

@@ -652,6 +652,34 @@ def __init__(self, x):
 
         self.assertEqual(set(weakset), set([depickled1, depickled2]))
 
+    def test_ignoring_whichmodule_exception(self):
+        class FakeModule(object):
+            def __getattr__(self, name):
+                # This throws an exception while looking up within
+                # pickle.whichimodule.
+                raise Exception()
+
+        class Foo(object):
+            __module__ = None
+
+            def foo(self):
+                return "it works!"
+
+        def foo():
+            return "it works!"
+
+        foo.__module__ = None
+
+        sys.modules["_fake_module"] = FakeModule()
+        try:
+            # Test whichmodule in save_global.
+            self.assertEqual(pickle_depickle(Foo()).foo(), "it works!")
+
+            # Test whichmodule in save_function.
+            self.assertEqual(pickle_depickle(foo)(), "it works!")
+        finally:
+            sys.modules.pop("_fake_module", None)
+
 
 if __name__ == '__main__':
     unittest.main()