ssh with multiplexing fails after connection and leaves zombie ssh processes

[Jim Garrison]

On 3/28/2025 02:36, Corinna Vinschen via Cygwin wrote:
> 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

'Tis a pity... but I do understand there are some things *nix can do 
that are just not possible to accomplish or emulate in the Windows domain.

Thanks for the reply.

-- 
Jim Garrison
jhg@acm.org