How to fix sudo: add-apt-repository: command not found using sudo add-apt-repository ppa:some/ppa in Ubuntu Linux Systems. If you get the error message “sudo: add-apt-repository: command not found” while adding sudo add-apt-repository ppa:some/ppa, here is what to do: sudo apt-get update sudo apt-get upgrade sudo apt-get install software-properties-common No run the respective command for adding the […]