package lightdm 1.17.5-0ubuntu2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[zakaria daaif]

desplay

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: lightdm 1.17.5-0ubuntu2
ProcVersionSignature: Ubuntu 4.4.0-3.17-generic 4.4.1
Uname: Linux 4.4.0-3-generic i686
ApportVersion: 2.19.4-0ubuntu2
Architecture: i386
Date: Sat Feb 6 00:30:33 2016
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationDate: Installed on 2016-02-04 (1 days ago)
InstallationMedia: Ubuntu-MATE 16.04 LTS "Xenial Xerus" - Alpha i386 (20160127)
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1
 apt 1.1.10
SourcePackage: lightdm
Title: package lightdm 1.17.5-0ubuntu2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

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

[Winfried PLappert (winfried-plappert)]

I just did a fresh install of ubuntu-mate 16.04-alpha2, then I updated the kernel to 4.4.0-2-generic.
Reboot, sudo apt-get update && sudo apt-get upgrade. And bingo, the error popped up.

[Martin Pitt (pitti)]

This is another fallout similar to bug 1540568. Unfortunately mate alpha-2 has that broken init-system-helpers version (1.26ubuntu1). To clean up, run

  sudo update-rc.d mountkernfs.sh defaults
  sudo update-rc.d dbus defaults
  sudo apt-get -f install