Do I understand correctly that the issue is that python Pickler class has dispatch attribute but C Pickler does not?  The add_dispatch_check-0.patch patch does not seem to add class attribute, it adds an instance attribute instead.

I also noticed that there are many more class attributes that only Python implementation has:

>>> for x in dir(pickle._Pickler):
...    if not (x.startswith('_') or hasattr(pickle.Pickler, x)):
...       print(x)
... 
dispatch
get
memoize
put
save
save_bool
save_bytes
save_dict
save_float
save_global
save_list
save_long
save_none
save_pers
save_reduce
save_str
save_tuple


The save_* methods are clearly internal and should probably be renamed to begin with __ unless they are intended to be overridden by Pickler subclases