Comment 4 for bug 837275

Very odd: it worked yesterday, and not this morning. I'm on 12.04 beta so a lot of packages are getting updated but I think this might be in virt-manager somewhere.

Guessing at reproduction:
1. Install virt-manager
2. Connect to libvirt running on a different host using qemu+ssh connection. E.g. `virt-manager -c qemu+ssh://root@hypervisor/system`
3. Double click on a running VM to see its VNC connection.
4. See "Error: viewer connection to hypervisor host go refused or disconnected! Error: ssh: connect to host 127.0.0.1 port 5900: Connection refused."
5. `virt-viewer -c qemu+ssh://root@hypervisor/system my-vm` does work

I believe the *different* host is the key. Reading ~/.virt-manager/virt-manager.log from days ago and now it looks like the command it is using has changed to no longer try to connect remotely.

From a few days ago when it worked:
[Mon, 02 Apr 2012 15:46:09 virt-manager 19288] DEBUG (console:1081) Starting connect process for proto=vnc trans=ssh connhost=hypervisor connuser= connport=None gaddr=127.0.0.1 gport=5903 gsocket=None
[Mon, 02 Apr 2012 15:46:09 virt-manager 19288] DEBUG (console:109) Creating SSH tunnel: ssh hypervisor sh -c 'nc -q 2>&1 | grep "requires an argument" >/dev/null;if [ $? -eq 0 ] ; then CMD="nc -q 0 127.0.0.1 5903";else CMD="nc 127.0.0.1 5903";fi;eval "$CMD";'
[Mon, 02 Apr 2012 15:46:09 virt-manager 19288] DEBUG (console:132) Tunnel PID=18467 OUTFD=56 ERRFD=58
[Mon, 02 Apr 2012 15:46:09 virt-manager 19288] DEBUG (console:992) Viewer connected
[Mon, 02 Apr 2012 15:55:56 virt-manager 19288] DEBUG (console:150) Shutting down tunnel PID=18467 OUTFD=56 ERRFD=58
[Mon, 02 Apr 2012 15:55:56 virt-manager 19288] DEBUG (console:964) Viewer disconnected

Today:
[Wed, 04 Apr 2012 08:17:38 virt-manager 26335] DEBUG (console:1075) Starting connect process for proto=vnc trans=ssh connhost=127.0.0.1 connuser=root connport=5901 gaddr=127.0.0.1 gport=5901 gsocket=None
[Wed, 04 Apr 2012 08:17:38 virt-manager 26335] DEBUG (console:109) Creating SSH tunnel: ssh -p 5901 -l root 127.0.0.1 sh -c 'nc -q 2>&1 | grep "requires an argument" >/dev/null;if [ $? -eq 0 ] ; then CMD="nc -q 0 127.0.0.1 5901";else CMD="nc 127.0.0.1 5901";fi;eval "$CMD";'
[Wed, 04 Apr 2012 08:17:38 virt-manager 26335] DEBUG (console:132) Tunnel PID=27507 OUTFD=24 ERRFD=26
[Wed, 04 Apr 2012 08:17:38 virt-manager 26335] DEBUG (console:150) Shutting down tunnel PID=27507 OUTFD=24 ERRFD=26

In the first it is trying to connect to the hypervisor, in the first it is trying to connect to localhost (which isn't doing anything).