This bug was fixed in the package gnome-session - 3.29.90-1ubuntu1

---------------
gnome-session (3.29.90-1ubuntu1) cosmic; urgency=medium

  * Merge with debian, remaining changes:
    - debian/control.in:
      + Recommend session-migration
      + Move xwayland dependency to gnome-session and make gnome-session
        Arch: any
      + Split gnome-startup-applications to a separate binary package so
        that it can be uninstalled without breaking the system
      + Add unity-session
    - Split ubuntu-session out of gnome-session.
    - Add upstart user session and systemd user session:
      debian/data, debian/gnome-session-bin.user-session.upstart
    - debian/gnome-session-bin.postinst, debian/gnome-session-bin.prerm:
       Moved registering gnome-session binary as a session manager to
       gnome-session-bin package
    - Add gnome-session-wayland transitional package
    - don't install gnome-mimeapps.list (installed by desktop-file-utils in
      Ubuntu):
      debian/gnome-session-common.dirs, gnome-session-common.install,
      gnome-session-common.maintscript, gnome-session-common.postinst
    - debian/patches/103_kill_the_fail_whale.patch:
      + Kill the Fail Whale as it tends to be more annoying than helpful
    - debian/patches/22_support_autostart_delay.patch:
      + Bugzilla patch to support adding a delay to autostart apps, using
        a "X-GNOME-Autostart-Delay" key in the desktop file
    - debian/patches/50_ubuntu_sessions.patch:
      + Add ubuntu session tweaks
    - debian/patches/51_remove_session_saving_from_gui.patch:
      + Add GNOME_SESSION_SAVE environment variable for people wanting to
        use the save session still, knowing that it can break your system
        if used unwisely
    - debian/patches/53_add_sessionmigration.patch:
      + launch session-migration if present at the start of the session.
        This sync tool runns different session migration scripts that can be
        provided in various desktop packages.
    - debian/patches/95_dbus_request_shutdown.patch:
      + Add "RequestShutdown" and "RequestReboot" DBus methods to allow
        other applications to shutdown or reboot the machine via the session
        manager.
    - debian/patches/ignore_gsettings_region.patch:
      + Ignore the "region" gsettings value - users' setting of LC_*
        variables saved in ~/.pam_environment.
    - debian/patches/revert_remove_gnome_session_properties.patch:
      + Don't merge translations into gnome-session-properties.desktop
  * debian/patches/50_ubuntu_sessions.patch:
    - moved to debian/patches/ubuntu/ubuntu-sessions.patch (using gbp topic)

  [ Didier Roche ]
  * Remove gnome-themes-extra and gtk2-engines-pixbuf Recommends.
    Those are pulled by the themes as needed.
  * ubuntu-session now depends on yaru-theme-gnome-shell, as the mod
    refers to it. (LP: #1783571)

gnome-session (3.29.90-1) experimental; urgency=medium

  * New upstream revision
  * debian/*: Update for experimental (3.29/3.30 series)
  * debian/patches/debian/Revert-main-Remove-GNOME_DESKTOP_SESSION_ID-envvar.patch:
    - revert removal of GNOME_DESKTOP_SESSION_ID not to break apps using it

gnome-session (3.28.1-1) unstable; urgency=medium

  * New upstream release
  * Drop patch included in new release

 -- Marco Trevisan (Treviño) <email address hidden>  Fri, 17 Aug 2018 03:12:08 +0200