Introduction

The ‘add-apt-repository command not found’ Ubuntu error appears when trying to add a new software repository. This indicates that the add-apt-repository is missing on your system.

This tutorial resolves the ‘add-apt-repository command not found’ error on Ubuntu and Debian-based Linux distributions..

resolve add-apt-repository command not found error ubuntu

Prerequisites

Steps to Resolve add-apt-repository: command not found error

Step 1: Update Local Ubuntu Repositories

Open a terminal window and enter the command to update repositories:

sudo apt-get update

The system confirms that the software repositories list on your local machine is updating.

example of apt-get update in ubuntu

Step 2: Install the software-properties-common Package

The add-apt-repository command is not a regular package that can be installed with apt on Debian / Ubuntu LTS 18.04, 16.04, and 14.04. Instead, it’s a component of the software-properties-common package.

To get the add-apt-repository command, install the software-properties-commont package:

sudo apt-get install software-properties-common

This is an example output after sucessful installation:

sudo apt-get installing software properties package


In Ubuntu 13.10 (and older), the add-apt-repository command is part of the Python software package. To install it, use the command:

sudo apt-get install python-software-properties


How To Add Apt Repository In Ubuntu & Debian

Certain software packages aren’t included in the default repositories. To make installing easier, developers created their own software repositories. This is where the add-apt-repository command is used.

For example, Wine is a popular package for running non-Linux software on a Linux system. But the latest version isn’t available through the default repositories.

To install the latest version of Wine on Ubuntu, you’d first need to grant access to the Wine repository:

sudo apt-add-repository ‘deb https://dl.winehq.org/wine-builds/ubuntu/ bionic main’

Other software may be subject to additional licensing. Such as in the case of Debian, restrictive licensing may disqualify a package from being included in the default repositories. In these cases, the add-apt-repository command is the key to grant access to the software you want to install.

What is a Repository in Ubuntu

A software package is an application. In certain cases one package needs other packages (called dependencies) to run. A package manager does the work of loading the software package you want. If there are any dependencies, the package manager installs those as well. Additionally, a package manager automatically keeps track of all installed software and updates.

A package manager works in tandem with a software repository. A repository is a database of many different software packages. By default, each Linux distribution grants access to a set of basic, default repositories.

In Ubuntu, the default repositories are:

  • Main – Free and open-source software from the Ubuntu developers
  • Universe – Free and open-source software from the Linux community
  • Restricted – Device drivers and other software under licensing from manufacturers
  • Multiverse – All other software under copyright or legal restriction

In Debian, the default repositories are:

  • Main – Free licensed software
  • Contrib – Free software that depends on non-free licensed software
  • Non-free – Software with restrictions on use and distribution

If you want to install a software package that’s not included in these default repositories, you need to add that repository to your package manager.

Conclusion

In this tutorial, you learned to use the add-apt-repositories command in Ubuntu or Debian to resolve the repository not found error.

You have also gained insight into software repositories and package management and the value they bring to maintaining your systems and keep them at optimum levels.