How to fix Duplicate sources.list entry?

Question

I keep getting this warning whenever I try to run sudo apt-get update.

W: Duplicate sources.list entry http://archive.ubuntu.com/ubuntu/ precise-updates/main i386 Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_precise-updates_main_binary-i386_Packages)
W: You may want to run apt-get update to correct these problems

Below is the output from /etc/apt/sources.list file:

deb http://archive.ubuntu.com/ubuntu precise main restricted
deb-src http://archive.ubuntu.com/ubuntu precise main restricted

deb http://archive.ubuntu.com/ubuntu precise-updates main restricted
deb-src http://archive.ubuntu.com/ubuntu precise-updates main restricted

deb http://archive.ubuntu.com/ubuntu precise universe
deb-src http://archive.ubuntu.com/ubuntu precise universe
deb http://archive.ubuntu.com/ubuntu precise-updates universe
deb-src http://archive.ubuntu.com/ubuntu precise-updates universe

deb http://archive.ubuntu.com/ubuntu precise multiverse
deb-src http://archive.ubuntu.com/ubuntu precise multiverse
deb http://archive.ubuntu.com/ubuntu precise-updates multiverse
deb-src http://archive.ubuntu.com/ubuntu precise-updates multiverse

deb http://archive.ubuntu.com/ubuntu precise-security main restricted
deb-src http://archive.ubuntu.com/ubuntu precise-security main restricted
deb http://archive.ubuntu.com/ubuntu precise-security universe
deb-src http://archive.ubuntu.com/ubuntu precise-security universe
deb http://archive.ubuntu.com/ubuntu precise-security multiverse
deb-src http://archive.ubuntu.com/ubuntu precise-security multiverse

How do I fix it?

Answer 1

I had the same problem, open software sources. unchecked "Canonical Partners". The Conflict is between "Canonical Partners" and " Canonical partners Added by software Center"

Answer 2

If you couldn't figure it out in your source.list, then do this:

1. Left-click on settings icon (at the extreme top corner of your screen) and select System Settings.
2. Click on Software Sources and move to Other Software.
3. Uncheck one of the 'Canonical Partners(Source Code) -software packaged by Canonical for their partners' files and one of the 'Canonical Partners -software packaged by Canonical for their partners' files also and click Close to leave.
4. Simultaneously press CTRL+ALT+T keys to open terminal and type sudo apt-get update.

Answer 3

It sounds like you have two identical lines in your /etc/apt/sources.list file.

Go to terminal, and enter sudo editor /etc/apt/sources.list, then look for any identical lines in that file, and if you find them, delete them. After your done, save and exit, and then do sudo apt-get update and that should resolve your problem.

If that doesn't solve your problem then you're going to have to use the trail and error approach. First, create a backup of your sources.list file, then in the actual file go through and comment out or delete each line, saving and apt-get update-ing after each line has been commented out or deleted. Going through this file line by line commenting out different lines will eventually tell you which line is the superfluous one. Don't forget to uncomment any lines you commented if apt-get update still shows the same prompt, otherwise you'll be left with no sources in your sources.list file.

Answer 4

Did you check ls /etc/apt/sources.list.d/? Maybe you have some "extra" repositories in there?

Answer 5

In my case the duplicates were in the prerequists-sources.list file. I was able to continue the upgrade by running the following commands in the Terminal:

sudo mv /etc/apt/sources.list.d/prerequists-sources.list /tmp
sudo apt-get update

Then go to the Update Manager and install the updates.

Answer 6

Just sudo gedit sources.list of the file where the Duplicate is and remove the line or put the # before the line!