Method 'UpdateActivationEnvironment' is only available at the canonical object path '/org/freedesktop/DBus'

Looks like the latest upstart change have generated these xsession-errors:

upstart (1.13.2-0ubuntu23) yakkety; urgency=medium

  * Cherry-pick upstream fix to publish global session variable changes to
    the dbus environment. LP: #1433013.

 -- Steve Langasek <email address hidden> Fri, 29 Apr 2016 14:38:53 -0700

ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: upstart 1.13.2-0ubuntu23
ProcVersionSignature: Ubuntu 4.4.0-21.37-generic 4.4.6
Uname: Linux 4.4.0-21-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_modeset nvidia
.etc.init.whoopsie.override: manual
ApportVersion: 2.20.1-0ubuntu3
Architecture: amd64
CurrentDesktop: GNOME
Date: Fri May 6 08:44:30 2016
ProcKernelCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-21-generic root=UUID=7c755ed6-51cc-4b75-88ac-9c75acf82749 ro
SourcePackage: upstart
UpgradeStatus: No upgrade log present (probably fresh install)
UpstartBugCategory: System
UpstartRunningSessionVersion: upstart 1.13.2
UpstartRunningSystemJobs:
 Error: command ['initctl', '--system', 'list'] failed with exit code 1: initctl: Name "com.ubuntu.Upstart" does not exist
UpstartRunningSystemVersion: Error: command ['initctl', '--system', 'version'] failed with exit code 1: initctl: Name "com.ubuntu.Upstart" does not exist
upstart.upstart-event-bridge.log: upstart-event-bridge stop/pre-start, process 1892