Comment 7 for bug 1812247

@paelzer, you put a lot of work into this. Much appreciated! Thanks a lot!

There's an important difference between your approach and mine: You start another ssh-agent within a terminal that you do not leave. So, this ssh-agent is available, it's plain OpenSSH ssh-agent, nothing seems to interfere, and everything works fine. I can confirm this.

However, an ssh-agent is already running, started by the X (or GNOME) session. And that's the ssh-agent we want to use so that the keys are available to all programs started by the window manager (e.g. a file manager accessing sftp://...).

Thanks to your input, though, and thanks to the fact that I got a new VirtualBox set up, I found that it's not just `ssh-add -c` that is failing. ssh-askpass itself (tried with the plain X11 one and the GNOME version) is not shown when it should.

So, I got a step further but, unfortunately, I still don't know where the actual bug is located. I am confused by a (new?) feature of GNOME keyring (I think) that makes locally saved SSH keys available and presents a full-screen dialog to ask for the password of the key.

There are 2 big problems with this:

(1) It works only for locally saved keys, but we want ssh-agent to receive keys via ssh-add from anywhere (e.g. a remote server via `ssh -A`).

(2) This dialog is not ssh-askpass. So, if ssh-askpass is supposed to work it does not. Hence, `ssh-add -c` and key confirmations fail, too.

I am attaching my full console session in Ubuntu 18.04.1 for reference and details.