I can sympathise with how you feel. Recently I spent several weeks trying to debug my build of 3.2dev on a Mac. Very frustrating, but I got there in the end. Turned out that the boost library I was using had been upgraded! Once I adjusted it to be the same as the one used in SuperCollider all was well again.
One word of caution about doing your own build on the latest 3.2dev source. recently there has been a revision of the layout of files in the gui/qt folder. Make sure you base your build on a recipe which is up to date. The post I did recently about building on a Raspberry Pi4 gives an indication of what is involved, although it would have to be tweaked for archlinux.