package initramfs-tools 0.122ubuntu8.16 failed to install/upgrade: subprocess installed post-installation script returned error exit status 127

[Kaushal Sharma]

This problem occurred trying to upgrade the ubuntu from 16.04 to 18.04

ProblemType: Package
DistroRelease: Ubuntu 18.04
Package: initramfs-tools 0.122ubuntu8.16
ProcVersionSignature: Ubuntu 4.15.0-74.83~16.04.1-generic 4.15.18
Uname: Linux 4.15.0-74-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.21
Architecture: amd64
Date: Thu Jan 23 23:42:23 2020
DuplicateSignature:
 package:initramfs-tools:0.122ubuntu8.16
 Processing triggers for initramfs-tools (0.122ubuntu8.16) ...
 /usr/sbin/update-initramfs: 222: /usr/sbin/update-initramfs: awk: not found
 dpkg: error processing package initramfs-tools (--unpack):
  subprocess installed post-installation script returned error exit status 127
ErrorMessage: subprocess installed post-installation script returned error exit status 127
InstallationDate: Installed on 2019-07-25 (182 days ago)
InstallationMedia: Ubuntu 16.04.6 LTS "Xenial Xerus" - Release amd64 (20190227)
PackageArchitecture: all
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.6
 apt 1.2.32
SourcePackage: initramfs-tools
Title: package initramfs-tools 0.122ubuntu8.16 failed to install/upgrade: subprocess installed post-installation script returned error exit status 127
UpgradeStatus: Upgraded to bionic on 2020-01-23 (0 days ago)