Normally I use aptitude upgrade or aptitude full-upgrade to get my system up to date. Since I am fiddling around with Vbox installation, I followed https://wiki.debian.org/VirtualBox strictly and added deb http://httpredir.debian.org/debian/ sid main contrib non-free to /etc/apt/sources.list and ran apt update, which apparently gives much more information about the installation process than aptitude including a lot of Error messages. So I started fixing these (e.g. NO_PUBKEY, superfluous cdrom entries, etc.). While searching the web to solve a few issues, I see the plasma update icon "Updates available" popping up. Okay, taking a look ... it shows "2584 packages to update" with more than 2 GiB to download ... and the count and volume are steadily growing as I write this question!

All seem to be not system relevant, just applications like Activity Pager, Akregator, and so on which I don't remember to have ever installed.

What did I do wrong? How to fix this? And why do I get updates for packages I don't recall to have ever installed?

I am running Debian Buster with KDE Plasma.

UPDATE: if the Sid line in sources.list is commented out, then the update request disappears; however something starts downloading from the internet (not sure yet what and why) whenever the network is connected

  • 1
    You’re not following the right instructions for your release. You need to follow the instructions for Debian 10. Apr 15, 2021 at 16:08
  • I didn't think of sid as a release, but more of a specification for buster (like free=/=non-free, stable=/=unstable). But you are right and I guess I should not compromise my system. Apr 15, 2021 at 17:00

1 Answer 1


Adding sid to your sources.list will upgrade all the packages from debian buster to sid (the development branch).

If you need to stay stable, remove the following line from your /etc/apt/sources.list:

deb http://httpredir.debian.org/debian/ sid main contrib non-free

Then run :

sudo apt update && sudo apt upgrade

Can I use Sid packages on "stable" or "testing"?

Trying to do so is highly discouraged. Attempting to mix packages between Debian repositories will likely create an unusable system. For more information about best practices, check out DontBreakDebian.

If you wish to use newer software, it is best to install packages from Backports.

Answer the question update: After commenting the SID repository apt will download the package index based on /etc/apt/sources.list, it will be used later to upgrade the packages.

Answer the comment: So this is a "one time" event? As I like to run Vbox on my machine, I guess I should upgrade to Sid -- or does it get very unstable?

To install virtual box in debian buster see the instruction here:

Add the following line to your /etc/apt/sources.list:

deb [arch=amd64] https://download.virtualbox.org/virtualbox/debian buster contrib


wget -q https://www.virtualbox.org/download/oracle_vbox_2016.asc -O- | sudo apt-key add -
wget -q https://www.virtualbox.org/download/oracle_vbox.asc -O- | sudo apt-key add -
sudo apt-get update
sudo apt-get install virtualbox-6.1

Adding Sid to stable will make your system unstable and my lead to a broken packages, it will be hard to find the system stability. See SystemDowngrade.

If you need to migrate to unstable, edit your sources.list, use only the following line:

deb http://httpredir.debian.org/debian/ sid main contrib non-free

then run:

sudo apt update && sudo apt dist-upgrade


  • So this is a "one time" event? As I like to run Vbox on my machine, I guess I should upgrade to Sid -- or does it get very unstable? Apr 15, 2021 at 15:50
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    You can upgrade the debian os but you can't downgrade the debian os - you have to do a new install in order to downgrade. Apr 15, 2021 at 16:10
  • After I added sid to sources.list, I ran apt update, but as this was immediately afterwards not much was updated and I started to work on the error messages. So I think my system is still "stable" or "buster" and not "sid". However, I am tempted to try sid hoping that vbox will work. Apr 15, 2021 at 16:44
  • @I'mnotabug--I'mafeature see my edit please.
    – GAD3R
    Apr 15, 2021 at 21:06
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    @GAD3R - Thanks! Backports is the way to go and not sid (at least in my case). Apr 16, 2021 at 3:24

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