# apt-get update

Hit:1 http://gb.archive.ubuntu.com/ubuntu xenial InRelease

Hit:2 http://gb.archive.ubuntu.com/ubuntu xenial-updates InRelease

Get:3 http://gb.archive.ubuntu.com/ubuntu xenial-backports InRelease [102 kB]

Ign:4 http://download.opensuse.org/repositories/home:/laszlo_budai:/syslog-ng/xUbuntu_16.10 ./ InRelease

Hit:5 http://download.opensuse.org/repositories/home:/laszlo_budai:/syslog-ng/xUbuntu_16.10 ./ Release

Get:6 http://security.ubuntu.com/ubuntu xenial-security InRelease [102 kB]

Fetched 204 kB in 0s (350 kB/s)

Reading package lists... Done

# apt-get install syslog-ng-core

Reading package lists... Done

Building dependency tree

Reading state information... Done

Some packages could not be installed. This may mean that you have

requested an impossible situation or if you are using the unstable

distribution that some required packages have not yet been created

or been moved out of Incoming.

The following information may help to resolve the situation:

The following packages have unmet dependencies:

 syslog-ng-core : Depends: libjson-c3 (>= 0.10) but it is not installable

E: Unable to correct problems, you have held broken packages.