I don't think this is a duplicate.
On a new install of 16.04.1 installing virt-manager should add ssh-askpass/ssh-askpass-gnome as a dependency. It even suggests the wrong package "openssh-askpass".
I don't think this is a duplicate.
On a new install of 16.04.1 installing virt-manager should add ssh-askpass/ ssh-askpass- gnome as a dependency. It even suggests the wrong package "openssh-askpass".