package fontconfig 2.12.6-0ubuntu2 failed to install/upgrade: triggers looping, abandoned

[vasilis]

error came up during distro upgrade from 16.04 to 18.04

ProblemType: Package
DistroRelease: Ubuntu 18.04
Package: fontconfig 2.12.6-0ubuntu2
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
Date: Mon Apr 30 22:06:01 2018
ErrorMessage: triggers looping, abandoned
InstallationDate: Installed on 2018-01-23 (96 days ago)
InstallationMedia: Ubuntu-MATE 16.04.3 LTS "Xenial Xerus" - Release amd64 (20170801)
Python3Details: /usr/bin/python3.6, Python 3.6.5, python3-minimal, 3.6.5-3
PythonDetails: /usr/bin/python2.7, Python 2.7.15rc1, python-minimal, 2.7.15~rc1-1
RelatedPackageVersions:
 dpkg 1.19.0.5ubuntu2
 apt 1.6.1
SourcePackage: fontconfig
Title: package fontconfig 2.12.6-0ubuntu2 failed to install/upgrade: triggers looping, abandoned
UpgradeStatus: Upgraded to bionic on 2018-04-30 (0 days ago)

[Launchpad Janitor (janitor)]

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