Weird font problem: No bold for you (kwin/konsole)

Hey guys,

I have the following problem that is weirding me out: Some of my programs just don’t make bold fonts like they used to anymore. This is what my systemsettings5 says my window titles should look like (I would use Open Sans 8 BOLD normally, but just for demonstration purposes I set it to EXTRABOLD):
And this is what kwin_x11 thinks I want:
It used to be MUCH BOLDER, and I can’t make it any bolder than this.

Similarly (or maybe completely unrelatedly), I cannot make konsole/yakuake use the BOLD variety of my font of choice, Dina, unless I re-set it EVERY SINGLE TIME I open a konsole window:
When I try to edit this profile, I can actually set it to Dina BOLD here, and it will work…
… until I restart it, at which point it falls back to Dina Regular.

My .local/share/konsole/Profil 1.profile looks like this:


Name=Profil 1

What’s more, this problem exists for ALL users on my PC, even if I create new users. The only thing that worked so far was a re-install–but now the problem has returned and I don’t want to re-install yet again.

So, what do I do now?

The lack of boldiness seems to affect other programs as well, e.g. dolphin and even systemsettings5.

So apparently, this is what happens:
When you change your fonts in systemsettings5, and you use “Open Sans Regular” for the general font, it sets this line in ~/.config/kdeglobals:

font=Open Sans,8,-1,5,50,0,0,0,0,0,Regular

As long as that “Regular” is in there, there are really no bold fonts in KDE applications. Removing “,Regular”, like so

font=Open Sans,8,-1,5,50,0,0,0,0,0

fixes all my font problems.
So it seems this is either a bug in systemsettings5, or whatever is interpreting ~/.config/kdeglobals.

(I’m using KDE Plasma 5.9.5, Frameworks 5.33.0, Qt 5.8.0 and KDE Apps 17.04.0, by the way.)

Relevant bug report on

As far as I can tell, even KDE developers dread Qt 5.8.