Python regression related to unix sockets

[Mark Geisert]

Hi Fabian,

Fabian Henze via Cygwin wrote:
> Hi Cygwin users,
> I noticed a regression in the recent Python packages: Between version
> 3.6.10-1 and 3.6.12-2, accessing the SSH agent via the paramiko python
> package broke. When a ssh agent is used, paramiko tries to connect to
> it via the unix socket and just freezes. Python 3.8 is also affected,
> but I don't know which was the last working one.
> I was able to pinpoint that error to 3.6.12-socketmodule.patch [1].
> Reverting/removing the patch fixes the ssh agent access.
> A few weeks ago there was a discussion regarding "Problems with native
> Unix domain sockets on Win 10/2019", but it seems unrelated as the
> cygwin1.dll from [2] does not work for me.
> 
> Can you please check if you are able to reproduce that? I uploaded a
> script [3] for that.
> 
> Best regards,
> Fabian Henze
> 
> [1] https://bugs.python.org/file49717/3.6.12-socketmodule.patch
> [2] https://cygwin.com/snapshots/x86_64/cygwin1-20210201.dll.xz
> [3] https://gist.github.com/henzef/4e553fad2335227b8f6b4550cd3fa543

Thanks for the report and sorry you've run into this.  The patch is a workaround 
that's evidently too draconian.  I will debug the situation using your testcase. 
Thank you very much for the testcase.

..mark