Restart button in Additional Drivers does not restart Xubuntu

[Thorpe]

After changing a driver in Additional Drivers tab of Software & Updates, a message tells me a restart ('You need to restart the computer to complete the driver changes.') is needed and introduces a button to restart the system. This button does not seem to do anything in Xubuntu 14.04.2.

Upon running software-properties-gtk through terminal and then clicking the restart button, these lines are printed:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/softwareproperties/gtk/SoftwarePropertiesGtk.py", line 1091, in on_driver_restart_clicked
    subprocess.call(['gnome-session-quit', '--reboot'])
  File "/usr/lib/python3.4/subprocess.py", line 533, in call
    with Popen(*popenargs, **kwargs) as p:
  File "/usr/lib/python3.4/subprocess.py", line 848, in __init__
    restore_signals, start_new_session)
  File "/usr/lib/python3.4/subprocess.py", line 1446, in _execute_child
    raise child_exception_type(errno_num, err_msg)
FileNotFoundError: [Errno 2] No such file or directory: 'gnome-session-quit'

'gnome-session-quit' does not work on Xubuntu with a fresh install.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: software-properties-gtk 0.92.37.3
ProcVersionSignature: Ubuntu 3.16.0-30.40~14.04.1-generic 3.16.7-ckt3
Uname: Linux 3.16.0-30-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.7
Architecture: amd64
CasperVersion: 1.340
CurrentDesktop: XFCE
Date: Fri Mar 6 15:45:48 2015
LiveMediaBuild: Xubuntu 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: software-properties
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

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

[era (era)]

I just got hit by this as well. The bug also triggered an Apport dialog, which (IMHO erroneously) pointed to https://bugs.launchpad.net/ubuntu/+source/software-properties/+bug/1167314.

I guess the action linked from the software-properties-gtk "Restart..." button ought to be configurable by a packaged setting. For XFCE, it looks (by quick googling) like "xfce4-session-logout --reboot" would be a suitable value for XUbuntu.

$ apt-cache policy software-properties-gtk
software-properties-gtk:
  Installed: 0.92.37.3
  Candidate: 0.92.37.3
  Version table:
 *** 0.92.37.3 0
        500 http://fi.archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
        100 /var/lib/dpkg/status
     0.92.36 0

$ grep -rF gnome-session-quit /usr/lib/python3/dist-packages/softwareproperties/gtk
Binary file /usr/lib/python3/dist-packages/softwareproperties/gtk/__pycache__/SoftwarePropertiesGtk.cpython-34.pyc matches
/usr/lib/python3/dist-packages/softwareproperties/gtk/SoftwarePropertiesGtk.py: subprocess.call(['gnome-session-quit', '--reboot'])

        500 http://fi.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages

$ lsb_release -rd
Description: Ubuntu 14.04.2 LTS
Release: 14.04

[era (era)]

It sure would be nice if there was a convenient portable way to find out how to reboot the desktop session with, say, "xdg-settings get desktop-reboot-command"; but, alas, there isn't.

http://portland.freedesktop.org/xdg-utils-1.1.0-rc1/scripts/xdg-settings looks like it would not be impossible to do, but I suspect that the hurdle is not primarily technical.

[Uwe Geuder (ubuntulp-ugeuder)]

Still the same problem on a fully updated xubuntu wily

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 15.10
Release: 15.10
Codename: wily

[Coya DeBrojara (coyadebrojara)]

I experience the same problem in xubuntu 16.04 alpha.

Distributor ID: Ubuntu
Description: Ubuntu Xenial Xerus (development branch)
Release: 16.04
Codename: xenial

4.4.0-7-generic x86_64 GNU/Linux