Synaptic fails to launch on Ubuntu 17.10

[Adam Dingle]

I'm trying out Ubuntu 17.10 (Artful). I installed Synaptic, but when I try to launch it from Activities nothing happens. If I try to launch it from a terminal, I see this:

adam@frontier:~$ sudo synaptic
[sudo] password for adam:
No protocol specified
Unable to init server: Could not connect: Connection refused

(synaptic:6737): Gtk-WARNING **: cannot open display: :0
adam@frontier:~$

[dino99 (9d9)]

Is it related to wayland ?
https://ubuntuforums.org/showthread.php?t=2366287&s=61571d9a60aae5135e64f4a026984b0e

[Adam Dingle (adam-yorba)]

I am running a Wayland session, so yes, it could be related:

adam@frontier:~$ echo $XDG_SESSION_TYPE
wayland
adam@frontier:~$

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Doug McMahon (mc3man)]

This happening in an ubuntu-wayland session is well known & expected behavior. However now it's occurring in the default ubuntu session which is new & hopefully unexpected behavior.
Note that some other apps would be also affected, example gparted

[Jeremy Bícha (jbicha)]

Adam, thanks for your bug report. I'm marking this bug a duplicate of bug 1551951 because that's the bug for Synaptic not working in GNOME (or Ubuntu) on Wayland.

Doug, please file a new bug for your issue. But I can't reproduce your issue here (Synaptic starts for me in the Ubuntu session on artful). Are you sure you aren't running Wayland?

Does running this command produce any output?
env | grep -i wayland

There was an issue last week where I think gdm3 was forcing Wayland when it should not have. So install all updates and restart your computer.

[corrado venturini (corradoventu)]

With the last daily BOTH sessions starts in Wayland, also the session named 'Ununtu'

[Roderic Jones (rodericj)]

I have been running 17.10 without a problem but updates over the weekend crashed the system. I have reinstalled from today's daily build and both sessions offered (Ubuntu or Ubuntu on Wayland) start the Wayland Desktop. Gdebi, Gparted and Synaptic do not work. The solution for me was to install the Nvidia driver and after a restart Wayland is no longer offered (Hooray!) and everything works OK.

[Ted Saker (tsaker)]

Pretty sure it's related to Wayland. I logged out, then logged back in on Ubuntu on X~ and both Synaptic and Gparted ran.