GNOME ssh askpass not working in 3.20?

[Paul Smith]

On Sat, 2016-06-11 at 12:31 -0400, Paul Smith wrote:
> This morning I updated my Ubuntu GNOME 16.04 LTS system to GNOME 3.20
> using the Gnome3 Staging PPA.
> 
> One issue is that somehow ssh is not longer asking for my passphrase
> using ssh-askpass.  Instead it always asks on the terminal and I need to
> enter it each time (it's not added to ssh-agent).  I didn't change
> anything about my personal configuration except install the GNOME 3.20
> packages and reboot.
> 
> If I run "ssh-add" by hand, then the key is added to the agent and it
> works properly, so the agent is running and configured properly.  It's
> only the ssh-askpass connection thing that is busted.
> 
> Anyone have any thoughts, or pointers to what I should look for?

No response yet :(.

However, I discovered a critical clue: on my Ubuntu GNOME 16.04 system
at work, which I have not upgraded to GNOME 3.20, I looked to see the
difference.

In both environments the SSH_AGENT_PID is set to the PID of an ssh-agent 
process, which is running using the same arguments.

_However_, at work my SSH_AUTH_SOCK value is set to
/run/user/$UID/keyring/ssh while at home my SSH_AUTH_SOCK is set
to /tmp/ssh-PYYRVK6N9zlP/agent.$SSH_AGENT_PID

If I change my SSH_AUTH_SOCK at home to be set to the same thing as at
work (that socket does exist, I checked), then everything works right!

So it seems that somehow during the upgrade to GNOME 3.20, the
startup/login sequence has been modified such that the "standard" ssh-
agent's value of SSH_AUTH_SOCK is taking precedence over the gnome-
keyring version of that variable (at least I assume something in GNOME
is creating the /run/user/.../ssh socket and maintaining it).

Anyone have any thoughts about this?