I'm not sure what happened, but add-apt-repository doesn't work anymore. If I try, it just hangs:
"[sudo] password for cyanogenhacker:"
and entering the password, it just flashes the cursor and does nothing for about thirty seconds. Afterwards it states
"Please check that the PPA name or format is correct."
despite having copied and pasted and verifying multiple times that the text is correct. It happens with every PPA I try (Docky, Numix, noobslab/themes)