okay, managed to fix whatever was ailing apt such that it doesn't want to uninstall half my software anymore (undid what i found in /var/log/apt/history.log), so now i'm just trying to find out if there's a way to get tde to peacefully coexist with qt5 stuff, without asking anybody to write or port anything, which i'm loath to do. if there's a way and somebody tells me of it, i'll report back on whether protonmail can be made to work with kmail as its client.