dill.loads(): AttributeError: can't set attribute

[githubdontbanmeagain]

Minimal reproduction steps

reproduce.py

import discord
import dill


class myClient:
    def __init__(self):
        self.client = discord.Client()

def main():
    data = {'client': myClient()}
    
    serialized = dill.dumps(data)
    print(serialized)
    
    unserialized = dill.loads(serialized)
    print(unserialized)


if __name__ == "__main__":
    main()

pip install discord.py-self
py reproduce.py

dumps() seems to work fine, but it fails at loads(). This is the traceback:

Traceback (most recent call last):
  File "C:\Users\x\reproduce.py", line 28, in <module>
    main()
  File "C:\Users\x\reproduce.py", line 18, in main
    unserialized = dill.loads(serialized)
  File "C:\Users\x\AppData\Local\Programs\Python\Python39\lib\site-packages\dill\_dill.py", line 303, in loads
    return load(file, ignore, **kwds)
  File "C:\Users\x\AppData\Local\Programs\Python\Python39\lib\site-packages\dill\_dill.py", line 289, in load
    return Unpickler(file, ignore=ignore, **kwds).load()
  File "C:\Users\x\AppData\Local\Programs\Python\Python39\lib\site-packages\dill\_dill.py", line 444, in load
    obj = StockUnpickler.load(self)
AttributeError: can't set attribute

Class which causes the error:
https://github.com/dolfies/discord.py-self/blob/master/discord/client.py#L144

Why is this happening? How can I prevent it?