When starting virt-manager from a system that does not have a dbus session running (e.g. when opening a remote ssh connection to a headless server), virt-manager quits immediately. There is no indication to the user that virt-manager could not connect to the dbus session or that the "--no-dbus" option should be supplied. This confuses the user as a proper error message is not provided in order to correct the action.
Should there instead be a warning/error message indicating that virt-manager failed to connect to the session bus?
Can you post the command line output when virt-manager is run with --no-fork in this case?
Hmm, I dont' see any dbus issues there. Both times you run those commands, no window pops up?
That second command will rightfully error: qemu:///localhost is not proper libvirt URI syntax. You would want to use qemu:///system most likely.
Thanks, closing as CURRENTRELEASE.