wip: working solution?

dill/_dill.py

@@ -31,6 +31,8 @@ def _trace(boolean):
 
 stack = dict()  # record of 'recursion-sensitive' pickled objects
 
+import abc
+
 import os
 import sys
 diff = None
@@ -1398,12 +1400,15 @@ def save_type(pickler, obj):
     elif obj.__module__ == '__main__':
         if issubclass(type(obj), type):
         #   try: # used when pickling the class as code (or the interpreter)
-            if is_dill(pickler, child=True) and not pickler._byref:
+            if is_dill(pickler, child=True) and not pickler._byref and not issubclass(type(obj), abc.ABCMeta):
                 # thanks to Tom Stepleton pointing out pickler._session unneeded
                 _t = 'T2'
                 log.info("%s: %s" % (_t, obj))
                 _dict = _dict_from_dictproxy(obj.__dict__)
         #   except: # punt to StockPickler (pickle by class reference)
+            if issubclass(type(obj), abc.ABCMeta):
+                StockPickler.save_type(pickler, obj)
+                return
             else:
                 log.info("T5: %s" % obj)
                 name = getattr(obj, '__qualname__', getattr(obj, '__name__', None))

tests/test_objects.py

@@ -23,6 +23,20 @@
 #extend(False)
 #import cloudpickle as pickle
 
+from abc import ABC, abstractmethod
+
+
+class OneTwoThree(ABC):
+
+    @abstractmethod
+    def foo(self):
+        pass
+
+class EasyAsAbc(OneTwoThree):
+
+    def foo(self):
+        print('bar')
+
 # helper objects
 class _class:
     def _method(self):
@@ -33,13 +47,17 @@ def _method(self):
 special['LambdaType'] = _lambda = lambda x: lambda y: x
 special['MethodType'] = _method = _class()._method
 special['UnboundMethodType'] = _class._method
+special['EasyAsABC'] = EasyAsAbc
+special['easy_as_abc'] = EasyAsAbc()
+special['OneTwoThree'] = OneTwoThree
 objects.update(special)
 
 def pickles(name, exact=False):
     """quick check if object pickles with dill"""
     obj = objects[name]
     try:
-        pik = pickle.loads(pickle.dumps(obj))
+        res = pickle.dumps(obj)
+        pik = pickle.loads(res)
         if exact:
             try:
                 assert pik == obj
@@ -49,8 +67,13 @@ def pickles(name, exact=False):
         else:
             assert type(obj) == type(pik)
     except Exception:
-        print ("fails: %s %s" % (name, type(obj)))
+        print("fails: %s %s" % (name, type(obj)))
+        raise
 
+def test_special():
+    pickles("EasyAsABC", exact=False)
+    pickles("OneTwoThree", exact=False)
+    pickles("easy_as_abc", exact=False)
 
 def test_objects():
     for member in objects.keys():
@@ -59,4 +82,5 @@ def test_objects():
 
 
 if __name__ == '__main__':
-    test_objects()
+    # test_objects()
+    test_lambda()