It seems that the fontconfig in KT 5.1.2 doesn't synthetically embolden for fonts that do not have bold face available any more.
So now if I only have a font of type Regular, I'll have to create a bold one manually for it. This is so boring and time-consuming, in addition to occupying more root partition.
I've looked through the configuration files in /etc/fonts/conf.d but find nothing helpful.
Could you guys confirm this? Thanks!