Since upgrading from F-10 to rawhide a few days ago, I've sometimes noticed that ssh-agent isn't present in my session after I log in through gdm. Other times, it works normally.
well, ssh-agent is not present, because it should be replaced by gnome-keyring. But that isn't apparently started either. And gnome-keyring should be started by gnome-session, so reassigning, but adding "me too".
gnome-keyring-daemon probably crashed. I've filed http://bugzilla.gnome.org/show_bug.cgi?id=577798 for the crash issues I am seeing.
gnome-keyring-daemon is run by default. For me the first attempt to use ssh pops up a passphrase dialog and login works. Subsequent attempts however print: Error reading response length from authentication socket. warren.XXX.XX's password: And gnome-keyring-daemon died. This began a few days ago for me.
Here the difference between not crashing and crashing is 2.26.0-1 vs 2.26.0-2, which points to the egg-endless-loop. Excerpt of the backtrace added here http://bugzilla.gnome.org/show_bug.cgi?id=575247
I've reverted the egg-endless-loop patch now, and commented on the upstream bug.