How to fix “Duplicate sources.list entry” warning?

Question

Every time I try to do some update (sudo apt-get update) it says:

Reading package lists ... ready
W: Duplicate sources.list entry http://archive.canonical.com/ubuntu/ need /partner amd64 Packages (/var/lib/apt/lists/archive.canonical.com_ubuntu_dists_precise_partner_binary-amd64_Packages)
W: Duplicate sources.list entry http://archive.canonical.com/ubuntu/ need /partner i386 Packages (/var/lib/apt/lists/archive.canonical.com_ubuntu_dists_precise_partner_binary-i386_Packages)
W: You have to run apt-get update to correct these problems

sources.list: http://paste.ubuntu.com/1180190/

ls /etc/apt/sources.list.d/ as requested:

milton@milton-HuronRiver-Platform:~$ ls /etc/apt/sources.list.d/
emesene-team-emesene-stable-precise.list
precise-partner.list
precise-partner.list.save
upubuntu-com-chat-precise.list
upubuntu-com-chat-precise.list.save

Answer 1

The partner repository is duplicated inside /etc/apt/sources.list and /etc/apt/sources.list.d/precise-partner.list.

Just remove those "precise-partner" files as the partner repository is already present in sources.list.

sudo rm /etc/apt/sources.list.d/precise-partner.*

Answer 2

Use the Ubuntu Sources List Generator.

• Run sudo nautilus in terminal
• /etc/apt/sources.list
• Right click and open the file with a text editor (if you click on it, it will open the software sources GUI)
• Simply copy and paste into the sources.list and save.
• Exit terminal and you're done.

Google seems to have a problem, so I'd suggest leaving that out. I have done this on Ubuntu 12.10 (Studio version with Ubuntu desktop added and Unity for another desktop sign in).