How to Add Ubuntu 20.04 Repository

GNU/Linux Ubuntu Enabling Ubuntu Focal Repo Guide

Hi! The Tutorial shows you Step-by-Step How to Add/Enable Ubuntu 20.04 Focal Repository in Ubuntu-Based GNU/Linux OSes.

And Ubuntu Focal Repo contains some Extra Stuff that you may want Installed on your System.

Especially relevant: using the Apt Pinning after this Setup the System Stability is Preserved.

Finally, this Setup is valid for all the Ubuntu Linux Based Distros like:

• Linux Mint
• Lubuntu
• Kubuntu
• Xubuntu
• Zorin OS
• Elementary OS
• Linux Lite
• Bodhi Linux
• Kde Neon
• Pop!_OS
• Voyager
• Trisquel
• LXLE
• feren OS
• Peppermint
• Q4OS
• Linux Ultimate Edition

1. 1. Launching Terminal

   How to QuickStart with Command Line on GNU/Linux

   Bash Shell Ubuntu QuickStart Guide

   Getting-Started with Terminal on Linux

2. 2. Adding Repo

   Then to Add Ubuntu Focal Repository
   Simply Copy and Execute this Command for the Universe:

   sudo su -c "echo 'deb [trusted=yes] http://cz.archive.ubuntu.com/ubuntu focal main universe multiverse' >> /etc/apt/sources.list.d/focal.list"

   Finally, Ctrl+x to Save & Exit from nano Editor :)

3. 3. Pinning Apt

   Then to make Apt Pinning Setup
   (Optional if you need to install only some Packages and after you disable it)
   And this is Fundamental to Preserve the Stability of the System in Case of Updates/Upgrades!
   So then Edit the Apt Preferences File with:

   sudo nano /etc/preferences

   And for a Ubuntu 22.04 Jammy Based Distro Append:

   Package: *
   Pin: release n=jammy
   Pin-Priority: 700
   
   Package: *
   Pin: release n=focal
   Pin-Priority: 600
   

   Instead, for a Ubuntu 18.04 Bionic Based Distro:

   Package: *
   Pin: release n=bionic
   Pin-Priority: 700
   
   Package: *
   Pin: release n=focal
   Pin-Priority: 600
   

   Ctrl+Shift+v to Paste in Code.
   And finally, Ctrl+x to Save & Exit from nano.
   Possibly to Find What’s your actual Repo Base use the cat Command like:

   cat /etc/apt/sources.list

   Or again look into the sources Directory to find out eventual others Repos:

   cat /etc/apt/sources.list.d/*.list

4. 4. Enabling Repo

   Finally, to Re-Load Repositories
   Do:

   sudo apt update

5. 5. Installing Single Package

   Finally, to Install One Package from Focal Repo
   Execute:

   sudo apt -t focal install [MYCOOLPACKAGE]

   So for instance:

   sudo apt -t focal install libgconfmm-2.6-1v5

6. 6. Disabling Repo

   Then in case to Remove Focal Repository
   Issue:

   sudo rm /etc/apt/sources.list.d/focal.list

   And after Update the Apt Sources again!