SUMMARY STEPS TO REPRODUCE 1. Install kdeinit5 from repositories where it's compiled without NDEBUG env variable (Kubuntu for example) 2. Start KDE session 3. Try finding a way to completely disable logging. OBSERVED RESULT https://cgit.kde.org/kinit.git/tree/src/kdeinit/kinit.cpp#n500 EXPECTED RESULT Possibility to control logging behaviour after compilation. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Kubuntu 18.04/Any KDE Plasma Version: any KDE Frameworks Version: any Qt Version: any ADDITIONAL INFORMATION Related bug: 361621
kdebugsettings turns off only part of these messages, check the provided link to source code to observe that it's impossible to control some logging after compilation.
I have basic CPP knowledge, I can try working on this issue if someone will show me a good example of a solution on fprintf I've linked to.
Fixed in master by removing kinit.