Adding this PPA to your system You can update your system with unsupported packages from this untrusted PPA by adding ppa:karl-qdh/ppa to your system's Software Sources. (Read about installing) sudo add-apt-repository ppa:karl-qdh/ppa sudo apt update This PPA can be added to your system manually by copying the lines below and adding them to your system's software sources. deb https://ppa.launchpad