Can't run apps requiring elevated privileges on artful

[Tom H]

On Wed, Oct 25, 2017 at 2:42 AM, Gilles Gravier <ggravier at fsfe.org> wrote:
>
> Have you noticed this: On a clean artful install, running an app that
> will require elevated privileges (like Synapic) won't work. You get
> the pop-up asking for your password, you enter it, then nothing
> happens.
>
> If you do this from a terminal by typing "sudo" and your command "sudo
> synaptic" or "sudo gnome-terminal" or any other graphical command you
> wish to run with elevated privileges, you always get the same error :
> Unable to init server: Could not connect: Connection refused
> Failed to parse arguments: Cannot open display:
>
> If you first open a terminal window and run "xhost +" then you can run
> these apps. But that's a kludgy workaround... and not easy to
> implement for apps that need to be launched at start of the graphical
> desktop session.
>
> Any ideas? I think it's a new bug (all this was working fine in 17.04).

There was a recent thread about this.

Synaptic (and other gui applications that need root privileges) needs
to use the polkit-and-dbus infrastructure under wayland.

[ "sudo gnome-terminal" doesn't make any sense. You can/should run
"sudo command" | "sudo -s" | "sudo su"| "sudo -i" | sudo su -" ]