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Date: Fri, 28 Mar 2025 10:36:58 +0100
To: cygwin AT cygwin DOT com
Subject: Re: ssh with multiplexing fails after connection and leaves zombie
 ssh processes
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From: Corinna Vinschen via Cygwin <cygwin AT cygwin DOT com>
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On Mar 27 16:11, Jim Garrison via Cygwin wrote:
> I just learned about ssh multiplexing and tried to set it up (Cygwin client
> to Debian server), but it fails to work and each attempt leaves a zombie ssh
> process.
> 
> According to the ssh -vvv debug output, authentication is successful but
> then fails during setup of the control master with
> 
>     mm_receive_fd: no message header
>     mux_master_process_new_session: failed to receive fd 0 from client
> 
> I found a StackOverflow post from over a decade ago indicating the problem
> is that Cygwin doesn't support file descriptor passing via unix-domain
> sockets.  https://stackoverflow.com/questions/20959792
> 
> Is it still true that ssh multiplexing is not available in Cygwin,

Yes.

> or is there a way to make it work?

Not without descriptor passing, sorry.


Corinna

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