Problem with 20110616 snapshot, ssh-agent, and mintty

Problem with 20110616 snapshot, ssh-agent, and mintty

[David Rothenberger]

I'm having a problem with recent snapshots, including the 20110616
snapshot. I normally start ssh-agent using keychain as part of my
bash startup. The problem I have is that once the bash process that
starts the ssh-agent process exits, subsequent starts of mintty
fail.

Here's an example:

----------------------------------------------------------------------
C:\Users\drothe>uname -a
CYGWIN_NT-6.1-WOW64 tela64 1.7.10s(0.248/5/3) 20110616 23:01:21 i686 Cygwin

C:\Users\drothe>bash --norc
bash-4.1$ mintty bash --norc -c 'ssh-agent'
bash-4.1$ mintty bash --norc
----------------------------------------------------------------------

That last start of mintty fails with the message "Failed to fork
child process: No such file or directory."

This is happening on my Win7 64-bit installation and my WinXP Pro
32-bit installation.

-- 
David Rothenberger  ----  daveroth@acm.org

The Second Law of Thermodynamics:
        If you think things are in a mess now, just wait!
                -- Jim Warner

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Re: Problem with 20110616 snapshot, ssh-agent, and mintty

[Corinna Vinschen]

On Jun 21 16:49, David Rothenberger wrote:
> I'm having a problem with recent snapshots, including the 20110616
> snapshot. I normally start ssh-agent using keychain as part of my
> bash startup. The problem I have is that once the bash process that
> starts the ssh-agent process exits, subsequent starts of mintty
> fail.
> 
> Here's an example:
> 
> ----------------------------------------------------------------------
> C:\Users\drothe>uname -a
> CYGWIN_NT-6.1-WOW64 tela64 1.7.10s(0.248/5/3) 20110616 23:01:21 i686 Cygwin
> 
> C:\Users\drothe>bash --norc
> bash-4.1$ mintty bash --norc -c 'ssh-agent'

I don't understand the sense in this one.  Shouldn't that be

  eval `ssh-agent`

so you set the environment variables for the subsequent processes?

> bash-4.1$ mintty bash --norc
> ----------------------------------------------------------------------
> 
> That last start of mintty fails with the message "Failed to fork
> child process: No such file or directory."

Right.  In the last call, when mintty opens a pty, Cygwin tries to
create tty0 because, apparently, it thinks tty0 is not in use.  This
fails with a "pipe busy".  For some reason ssh-agent still holds handles
to the pipes which constitute tty0 created by the mintty from which
it has been started but Cygwin forgot about it.

I applied a patch which seems to do the trick.


Thanks for the report,
Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

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Re: Problem with 20110616 snapshot, ssh-agent, and mintty

[David Rothenberger]

On 6/22/2011 12:58 AM, Corinna Vinschen wrote:
> On Jun 21 16:49, David Rothenberger wrote:
>> C:\Users\drothe>bash --norc
>> bash-4.1$ mintty bash --norc -c 'ssh-agent'
> 
> I don't understand the sense in this one.  Shouldn't that be
> 
>   eval `ssh-agent`
> 
> so you set the environment variables for the subsequent processes?

Of course. This was just a simple example to illustrate the problem.

> I applied a patch which seems to do the trick.

Thanks. I look forward to the next snapshot.

-- 
David Rothenberger  ----  daveroth@acm.org

vacation, n.:
        A two-week binge of rest and relaxation so intense that
        it takes another 50 weeks of your restrained workaday
        life-style to recuperate.

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