Downgrading kubuntu backports to official repositories: could not find package list for PPA

Question

I have added the Kubuntu backports PPA. This somehow messed up my system.

Now I want to remove the PPA and downgrade all the packages to the version provided in the official repositories.

I followed this AskUbuntu question and run ppa-purge. But it returned me the following error:

$ sudo ppa-purge http://ppa.launchpad.net/kubuntu-ppa/backports/ubuntu/ 
Updating packages lists
PPA to be removed: http://ppa.launchpad.net/kubuntu-ppa/backports/ubuntu ppa
Warning:  Could not find package list for PPA: http://ppa.launchpad.net/kubuntu-ppa/backports/ubuntu ppa

How can I solve it?

Answer 1

Solved it.

You have to re-add the PPA:

sudo add-apt-repository ppa:kubuntu-ppa/backports
sudo apt-get update

and the run ppa-purge using the PPA name, not the URL:

sudo ppa-purge ppa:kubuntu-ppa/backports