virt-manager / virt-install: unable to connect to 'localhost:8000': Connection refused

This should be a bug on Ubuntu 12.10 + Xen 4 + virt-manager. This problem also exists on Ubuntu12.04 LTS + Xen 4 + virt-install

Solution/Workaround:

In "/etc/xen/xend-config.sxp",


uncomment the following lines:
(xend-unix-server no)
(xend-unix-path /var/lib/xend/xend-socket)

Then, change
(xend-unix-server no)
to
(xend-unix-server yes)

Reboot.

Reference:
https://bugs.launchpad.net/ubuntu/+source/virt-manager/+bug/915954