package phonon-backend-null 4:4.10.0-2 failed to install/upgrade: conflicting packages - not installing phonon-backend-null:amd64

Wanting to install cirkuit software, I encountered a lot of issues related to dependencies. Indeed,
not easy to find libpoppler-qt4-dev under ubuntu-bionic distro. Afert rebooting the OS, I saw this
message : package phonon-backend-null 4:4.10.0-2 failed to install/upgrade: conflicting packages - not installing phonon-backend-null:amd64.

Thank you!

ProblemType: Package
DistroRelease: Ubuntu 18.04
Package: phonon-backend-null 4:4.10.0-2
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: Sat May 12 08:49:08 2018
ErrorMessage: conflicting packages - not installing phonon-backend-null:amd64
InstallationDate: Installed on 2018-02-08 (93 days ago)
InstallationMedia: Ubuntu 17.10 "Artful Aardvark" - Release amd64 (20180105.1)
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: phonon
Title: package phonon-backend-null 4:4.10.0-2 failed to install/upgrade: conflicting packages - not installing phonon-backend-null:amd64
UpgradeStatus: Upgraded to bionic on 2018-05-07 (4 days ago)