$ LANGUAGE=C sudo apt full-upgrade -o Debug::pkgProblemResolver=true
[sudo] password for soee:
Reading package lists... Done
Building dependency tree
Reading state information... Done
Starting pkgProblemResolver with broken count: 1
Starting 2 pkgProblemResolver with broken count: 1
Investigating (0) oxygen5-icon-theme [ amd64 ] < 5.18.0-0ubuntu1 -> 5.21.0-0ubuntu1~ubuntu16.04~ppa1 > ( x11 )
Broken oxygen5-icon-theme:amd64 Breaks on oxygen-icon-theme [ amd64 ] < 5:5.18.0-0ubuntu1 > ( universe/x11 )
Considering oxygen-icon-theme:amd64 29 as a solution to oxygen5-icon-theme:amd64 30
Added oxygen-icon-theme:amd64 to the remove list
Conflicts//Breaks against version 5:5.18.0-0ubuntu1~ubuntu16.04~ppa50 for oxygen-icon-theme but that is not InstVer, ignoring
Fixing oxygen5-icon-theme:amd64 via remove of oxygen-icon-theme:amd64
Investigating (1) kde-runtime [ amd64 ] < 4:15.12.3-0ubuntu1 > ( universe/kde )
Broken kde-runtime:amd64 Depends on oxygen-icon-theme [ amd64 ] < 5:5.18.0-0ubuntu1 > ( universe/x11 ) (>= 4:4.6)
Considering oxygen-icon-theme:amd64 29 as a solution to kde-runtime:amd64 50
Added oxygen-icon-theme:amd64 to the remove list
Fixing kde-runtime:amd64 via keep of oxygen-icon-theme:amd64
Investigating (1) oxygen5-icon-theme [ amd64 ] < 5.18.0-0ubuntu1 -> 5.21.0-0ubuntu1~ubuntu16.04~ppa1 > ( x11 )
Broken oxygen5-icon-theme:amd64 Breaks on oxygen-icon-theme [ amd64 ] < 5:5.18.0-0ubuntu1 > ( universe/x11 )
Considering oxygen-icon-theme:amd64 29 as a solution to oxygen5-icon-theme:amd64 30
Added oxygen-icon-theme:amd64 to the remove list
Conflicts//Breaks against version 5:5.18.0-0ubuntu1~ubuntu16.04~ppa50 for oxygen-icon-theme but that is not InstVer, ignoring
Fixing oxygen5-icon-theme:amd64 via remove of oxygen-icon-theme:amd64
Investigating (2) kde-runtime [ amd64 ] < 4:15.12.3-0ubuntu1 > ( universe/kde )
Broken kde-runtime:amd64 Depends on oxygen-icon-theme [ amd64 ] < 5:5.18.0-0ubuntu1 > ( universe/x11 ) (>= 4:4.6)
Considering oxygen-icon-theme:amd64 29 as a solution to kde-runtime:amd64 50
Added oxygen-icon-theme:amd64 to the remove list
Fixing kde-runtime:amd64 via keep of oxygen-icon-theme:amd64
Investigating (2) oxygen5-icon-theme [ amd64 ] < 5.18.0-0ubuntu1 -> 5.21.0-0ubuntu1~ubuntu16.04~ppa1 > ( x11 )
Broken oxygen5-icon-theme:amd64 Breaks on oxygen-icon-theme [ amd64 ] < 5:5.18.0-0ubuntu1 > ( universe/x11 )
Considering oxygen-icon-theme:amd64 50 as a solution to oxygen5-icon-theme:amd64 30
Holding Back oxygen5-icon-theme:amd64 rather than change oxygen-icon-theme:amd64
Try to Re-Instate (3) oxygen5-icon-theme:amd64
Done
Calculating upgrade... Done
The following packages have been kept back:
oxygen5-icon-theme
0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.