(As I'm sure you know) libc6-dev is a package used in C development, containing essential libs and header files. Why do I have it installed? Because I do occationally develop in C on-device. I however don't see why that would automatically imply that I "should" know what causes this dependency problem, mind you I don't recall having this issue for the numerous earlier CSSU updates.

What is the package name(s) for the CSSU, i.e. what is it trying to update? I could try to see what apt-get has to say but I'd prefer not to go that route if possible.

I could of course uninstall libc6-dev and the reinstall it when CSSU is updated, but I suppose there is a fat chance libc6-dev would then refuse to install, no? I should perhaps add that when I (late 2010) installed the build essentials I downloaded each package seperately and dpkg -i'd them, but I'm aware there is (and perhaps was) a composite package build-essential for that purpose.