fix: thanks to @rkern we now have a passing test with dynamic traits retaining their type through pickling

Author: satra

nipype/interfaces/base.py

@@ -499,36 +499,20 @@ def _get_sorteddict(self, object, dictwithhash=False, hash_method=None, hash_fil
                     out = object
         return out
 
+    def __getstate__(self):
+        state = super(BaseTraitedSpec, self).__getstate__()
+        inst_traits = self._instance_traits()
+        state['__instance_traits__'] = inst_traits
+        return state
+
+    def __setstate__(self, state):
+        inst_traits = state.pop('__instance_traits__', {})
+        for attr, trait in inst_traits.iteritems():
+            self.add_trait(attr, trait)
+        super(BaseTraitedSpec, self).__setstate__(state)
 
 class DynamicTraitedSpec(BaseTraitedSpec):
-    """ A subclass to handle dynamic traits
-
-    This class is a workaround for add_traits and clone_traits not
-    functioning well together.
-    """
-    def __deepcopy__(self, memo):
-        """ bug in deepcopy for HasTraits results in weird cloning behavior for
-        added traits
-        """
-        id_self = id(self)
-        if id_self in memo:
-            return memo[id_self]
-        dup_dict = deepcopy(self.get(), memo)
-        # access all keys
-        for key in self.copyable_trait_names():
-            _ = getattr(self, key)
-        # clone once
-        dup = self.clone_traits(memo=memo)
-        for key in self.copyable_trait_names():
-            try:
-                _ = getattr(dup, key)
-            except:
-                pass
-        # clone twice
-        dup = self.clone_traits(memo=memo)
-        dup.set(**dup_dict)
-        return dup
-
+    pass
 
 class TraitedSpec(BaseTraitedSpec):
     """ Create a subclass with strict traits.