python > 3.5: Issue with unix domain sockets

[Mark Geisert]

Marco Atzeri via Cygwin wrote:
> 
> On 04.05.2021 06:41, Mark Geisert wrote:
>> Ken Brown via Cygwin wrote:
>>> On 5/3/2021 8:57 AM, Maximilian.Blenk--- via Cygwin wrote:
>>>> Incorrect Behavior:
>>>> Server:
>>>> $ python3.7 server.py
>>>> starting up on ./uds_socket
>>>> waiting for a connection
>>>> Traceback (most recent call last):
>>>>    File "server.py", line 27, in <module>
>>>>      connection, client_address = sock.accept()
>>>>    File "/usr/lib/python3.7/socket.py", line 214, in accept
>>>>      sock = socket(self.family, self.type, self.proto, fileno=fd)
>>>>    File "/usr/lib/python3.7/socket.py", line 151, in __init__
>>>>      _socket.socket.__init__(self, family, type, proto, fileno)
>>>> SystemError: <slot wrapper '__init__' of '_socket.socket' objects> returned 
>>>> NULL without setting an error
>>>>
>>>> Client:
>>>> $ python3.7 client.py
>>>> connecting to ./uds_socket
>>>> sending b'This is the message.  It will be repeated.'
>>>> closing socket
>>>> Traceback (most recent call last):
>>>>    File "client.py", line 27, in <module>
>>>>      data = sock.recv(16)
>>>> ConnectionResetError: [Errno 104] Connection reset by peer
>>>
>>> I wonder if this has the same cause as the problem reported here:
>>>
>>>    https://cygwin.com/pipermail/cygwin/2021-February/247884.html
>>>
>>> Mark, can you check that?
>>
>> Hmm, the correlation between failing Python versions and patch placements is 
>> troubling.  I've reproduced the OP's findings and will dig further.
>>
>> ..mark
>>
> 
> 3.5 has not your patch for asyncio, as I am not updating it.
> 
> all the others have it. It will be nice to solve this problem and avoid the freeze 
> that your patch solved.

Agreed; fortunate here to have 3.5 frozen.  I see the cause.  I'm taking this to 
cygwin-developers and will respond here when we have a solution at hand.

..mark