How to fix add-apt-repository: command not found

Problem

When trying to add a PPA repository on Ubuntu or Debian, you might encounter the following error:

$ sudo add-apt-repository ppa:some/ppa
sudo: add-apt-repository: command not found

Solution

The add-apt-repository command is part of the software-properties-common package. To install it, run the following command:

sudo apt-get update
sudo apt-get install software-properties-common

After that, you should be able to use the add-apt-repository command without any issues.

In case you see the error message

E: Unable to locate package software-properties-common

you might be using Debian Trixie. For Debian Trixie, I don’t know a direct method of using add-apt-repository. Since PPAs are designed for Ubuntu, you might want to look for an alternative repository or consider upgrading to a more recent version of Debian or using Ubuntu if you need explicit PPA support.