package linux-image-4.15.0-20-generic 4.15.0-20.21~16.04.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 127

[santosh kumar kanithi]

package linux-image-4.15.0-20-generic 4.15.0-20.21~16.04.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 127

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: linux-image-4.15.0-20-generic 4.15.0-20.21~16.04.1
ProcVersionSignature: Ubuntu 4.15.0-15.16~16.04.1-generic 4.15.15
Uname: Linux 4.15.0-15-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.15
Architecture: amd64
Date: Wed May 9 07:20:07 2018
DistributionChannelDescriptor:
 # This is a distribution channel descriptor
 # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
 canonical-oem-somerville-xenial-amd64-20160624-2
DuplicateSignature:
 package:linux-image-4.15.0-20-generic:4.15.0-20.21~16.04.1
 Setting up linux-image-4.15.0-20-generic (4.15.0-20.21~16.04.1) ...
 /var/lib/dpkg/info/linux-image-4.15.0-20-generic.postinst: 50: /var/lib/dpkg/info/linux-image-4.15.0-20-generic.postinst: linux-update-symlinks: not found
 dpkg: error processing package linux-image-4.15.0-20-generic (--configure):
  subprocess installed post-installation script returned error exit status 127
ErrorMessage: subprocess installed post-installation script returned error exit status 127
InstallationDate: Installed on 2017-12-25 (134 days ago)
InstallationMedia: Ubuntu 16.04 "Xenial" - Build amd64 LIVE Binary 20160624-10:47
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.4
 apt 1.2.26
SourcePackage: linux-signed-hwe-edge
Title: package linux-image-4.15.0-20-generic 4.15.0-20.21~16.04.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 127
UpgradeStatus: No upgrade log present (probably fresh install)

[Olivier Louvignes (olouvignes)]

Can confirm this breaks unattended upgrades of 16.04 devices with hwe installed:

# dpkg-reconfigure linux-image-4.15.0-20-generic
/usr/sbin/dpkg-reconfigure: linux-image-4.15.0-20-generic is broken or not fully installed

# dpkg-reconfigure linux-image-4.15.0-20-generic --force
/var/lib/dpkg/info/linux-image-4.15.0-20-generic.postinst: 50: /var/lib/dpkg/info/linux-image-4.15.0-20-generic.postinst: linux-update-symlinks: not found

However I don't know how it can happen but the grub is modified, and it won't ever reboot.

root@player-3fd4:~# cat /boot/grub/grub.cfg | grep 4.15.0-20-generic | wc -l
10

We have lost hundreds of devices today after reboot with no seemingly possible remote intervention. This is going to be a nightmare for a lot of people...

[Launchpad Janitor (janitor)]

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

[Jeremy (wa113y3s)]

Check in terminal

apt policy linux-base

You need to have 4.5ubuntu1~16.04.1 installed or you get the error

/var/lib/dpkg/info/linux-image-4.15.0-20-generic.postinst: 50: /var/lib/dpkg/info/linux-image-4.15.0-20-generic.postinst: linux-update-symlinks: not found

A manual install with sudo apt install linux-image-4.15.0-20-generic might also have issues as the linux-modules-extra-4.15.0-20-generic will not be installed as a dependency in 16.04
linux-modules-extra is a dependency of linux-image-generic-hwe-16.04-edge

[Jeremy (wa113y3s)]

Possibly related to https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1767133