In this article I will tell you how to add any Debian repository with the ability to use it at any time you need.
For example, your current repository is stable. But suddenly you need a fresh version of the package, which is in a testing or unstable (sid) repository. Then you can easily add them and use them at any time convenient for you.
There is a very simple way to do this without setting priorities and other things. You just use these repositories when you really want it. OK, let’s do it.
Step by step. Specify our default repository
First, Go to /etc/apt/apt.conf.d directory
Then, create a 99defaultrelease file in it
Then open it and write your current default repository, so if my current default repository is stable, then I write
Then go to /etc/apt/sources.list.d direcory
Here you can add as many repositories as you like.
Start to specify additional repositories. How to add unstable repository
For example, we only want to add an unstable repository. Then we need create a file unstable.list in /etc/apt/sources.list.d directory
And write in it following URL addresses and options
deb http://ftp.uk.debian.org/debian/ unstable main contrib non-free deb-src http://ftp.uk.debian.org/debian/ unstable main contrib non-free #deb http://security.debian.org/ unstable main contrib non-free
Here I use English servers (I highlighted subdomains in bold), so you can change to any other. To choose the right server, check your /etc/apt/sources.list
And look, what servers do you use now, these are the servers that you chose when you installed Debian. You need exactly URL address. Or you can use this page (Debian worldwide mirror sites) to choose the needed servers. The geographical location of the server affects the speed of downloading packages.
I commented out the last line, because it is responsible for security packages, I don’t in any way want to use security packages from an unstable repository, so I commented out this line to make sure.
Then update the list of available packages.
sudo apt-get update
As you noticed, the information was downloaded from both the unstable and stable(if you use it) repository.
How to install unstable (sid) packages now?
You can install them this way
sudo apt-get -t unstable install some_package
It’s easy, right?
So, if you enter just
sudo apt-get install some_package
The package will be installed from the stable repository (if it is your default one).
How to add a testing repository
First, create a file testing.list in /etc/apt/sources.list.d directory
And add following lines
deb http://ftp.uk.debian.org/debian/ testing main contrib non-free deb-src http://ftp.uk.debian.org/debian/ testing main contrib non-free #deb http://security.debian.org/ testing main contrib non-free
Don’t forget to change the geographical location of the package server.
Then update the package list by command
sudo apt-get update
Now you can easily install packages from the testing repository with the command
sudo apt-get -t testing install some_package
Thanks for attention!