Kontact fails to start: KSycoca unavailable.

[Mehron Kugler]

$ lsb_release -rd
Description: Ubuntu 18.04.2 LTS
Release: 18.04

$ apt-cache policy kontact
kontact:
  Installed: 4:17.12.3-0ubuntu1
  Candidate: 4:17.12.3-0ubuntu1
  Version table:
 *** 4:17.12.3-0ubuntu1 500
        500 http://us.archive.ubuntu.com/ubuntu bionic/universe amd64 Packages
        100 /var/lib/dpkg/status

Steps to reproduce:

1. sudo apt-get install kontact
2. kontact

Expected results: Kontact starts
Actual result: The following error message:

KSycoca unavailable. Kontact will be unable to find plugins.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: kontact 4:17.12.3-0ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-46.49-generic 4.15.18
Uname: Linux 4.15.0-46-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.6
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Fri Apr 5 15:52:50 2019
InstallationDate: Installed on 2019-03-09 (27 days ago)
InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
SourcePackage: kontact
UpgradeStatus: No upgrade log present (probably fresh install)