dill_bugs breaks in pypy on save_wrapper_descriptor

[mmckerns]

As reported by @Peque:

$ pypy tests/dill_bugs.py 
True: <type 'str'>, __main__
True: <type 'function'>, <function _method at 0x0000000002534ea8>
Traceback (most recent call last):
  File "tests/dill_bugs.py", line 42, in <module>
    print ("%s: %s, %s" % (dill.pickles(i), type(i), i))
  File "/media/src/dill/dill/dill.py", line 1304, in pickles
    pik = copy(obj, **kwds)
  File "/media/src/dill/dill/dill.py", line 206, in copy
    return loads(dumps(obj, *args, **kwds))
  File "/media/src/dill/dill/dill.py", line 256, in dumps
    dump(obj, file, protocol, byref, fmode, recurse)#, strictio)
  File "/media/src/dill/dill/dill.py", line 249, in dump
    pik.dump(obj)
  File "/usr/lib64/pypy-4.0.1/lib-python/2.7/pickle.py", line 224, in dump
    self.save(obj)
  File "/usr/lib64/pypy-4.0.1/lib-python/2.7/pickle.py", line 286, in save
    f(self, obj) # Call unbound method with explicit self
  File "/media/src/dill/dill/dill.py", line 1008, in save_wrapper_descriptor
    pickler.save_reduce(_getattr, (obj.__objclass__, obj.__name__,
AttributeError: generic property has no __objclass__

[Peque]

Hi Mike, is there any update on this matter? 😇

[mmckerns]

@Peque: if there were, I'd update this ticket. I believe this is all that is needed for you to have the compatibility you want, but I have not had time to resolve this issue with the wrapper_descriptor just yet.

[Peque]

@mmckerns I understand. Thanks a lot for taking the time to reply anyway! 😊

[mmckerns]

I have opened a ticket on pypy at: https://bitbucket.org/pypy/pypy/issues/2464/getset_descriptor-cannot-access

[mmckerns]

There's now a patch for this in pypy. After some testing against the latest pypy, I think this should be able to be closed.

[mmckerns]

While it seems the current patch fixes the issue for some cases, it doesn't work in all cases. Also, there's an error in the pickling that is produced when the descriptors are a weakref. I'm punting the discussion to the pypy ticket until it's better suited to come back here.

[mmckerns]

While testing with the latest pypy (with the patch applied), I've found some other issues for pypy compatibility and fixed them in de597c5. Looks like now only the remaining issue is that descriptors for built-ins in pypy don't have an __objclass__ attribute - -and that would require a change to pypy. Otherwise, I don't see any further issues.

[mmckerns]

Another iteration with pypy. With, 5aa2636, looks like only the descriptor for __doc__ is missing the __objclass__ attribute. When this is patched in pypy, then I think this ticket can close.

[Peque]

Great news. I am subscribed to the Bitbucket's issue, following your discussion. 👍

[mmckerns]

I'm closing this, as it is fixed in the pypy nightly builds… and should roll into latest release soon enough.

[irmen]

By the way it looks like the recent dill release fixed the problems I was having with Pyro4 where it didn't work on pypy. Somehow I didn't even have to install the latest pypy nightly with the fixes on their end.

[mmckerns]

@irmen: I had some iterations with the pypy developers. pypy and dill both made some tweaks that have hopefully "solved the problem". I expect you may encounter a case that fails until the pypy release it out -- but maybe you won't, and that will be even better.