I don't know the ""ppa-purge" script. A good tool to identify from which source installed packages are coming seems to me "apt-get-versions". Piping the output to a grep command similar to the following for a mixed (from testing, unstable, and experimental) system $ apt-show-versions | grep -Ev '/(testing|unstable)' can assist finding candidate packages for further treatment. -- Best regards, Jörg-Volker.