Apologies if this is the wrong place. On El Capitan, I had no
problems with ssh X11 forwarding, but now now on Sierra 10.12.2
untrusted X11 forwarding setup failed: xauth key data not generated
or ssh -Y remote
No xauth data; using fake authentication data for X11 forwarding
and this doesn't appear to be harmless because
X11 connection rejected because of wrong authentication.
Error: Can't open display: localhost:10.0
and echo $DISPLAY
I have checked that ForwardX11 yes is in both my ssh_config and
Oh dear, I feel rather embarrassed; ssh -Y remote does solve my
problem. Now when I do echo $DISPLAY, I do get localhost:10.0
and xdvi works fine. Please accept my apologies.