Originally reported at http://bugs.debian.org/682555

"When I use gnome-boxes to access a remote system via vnc, if the remote system
is vnc password protected, instead of getting prompted for the password by
gnome-boxes, it simply hangs and does nothing.

Equally I am unable to pass the vnc password in the URL string e.g.
vnc://<user>:<password>@<remote host>:<port> OR
vnc://<remote host>:<port>?vncpasswd=<password>

which makes me think that this functionality is not implemented at all.
Since vnc password is a basic element of the vnc protocol, I think being able
to handle this feature is a useful addition to gnome-boxes."