Problem when upgrading to new version of glibc?

Here is an annoyning little problem that I kept running into when I wanted to upgrade to a newer version of glibc:

dpkg kept complaining that there is another version listed in /etc/ld.so.conf. Too bad it didn't say which line it was complaining about or which folder the offending files were in. So I commented out one line after another and ran ldconfig each time. Then I tried to upgrade again, but without any success.

Turn out that comments don't do the trick. You need to acutally delete the lines from /etc/ld.so.conf. (Why does nobody ever tell you these things?)