How bad are duplicate entries in sources.list? [duplicate]
Your sources.list really has duplicate entries.
First Let's see the correct form of a repository line or source line:
The correct format of repository source line is
<type of repository> <location> <dist-name> <components>
For example, a repo line can be like this one
deb http://archive.ubuntu.com/ubuntu precise main
Here, it means, the repository is for binary packages, which are hosted in http://archive.ubuntu.com/ubuntu and this repository is for Ubuntu precise (12.04) and this repository contains the main (software which are officially supported by Canonical) component.
Type: The type can be
deb
anddeb-src
.deb
means a binary repository wheredeb-src
means a source repositoryLocation:
http://archive.ubuntu.com/ubuntu
location of the repository.Dist-name: The distribution name of Ubuntu release. For Ubuntu 12.04 it is
precise
, for 11.10 it isoneiric
.
You can visit the Ubuntu Wiki to view an updated list of Ubuntu releases and their code names.Component: It can be
main
,universe
,multiverse
andrestricted
. These words indicates the level of supports for the packages and the licensing status.
See this page for more information.
Please take note that, you can add one or more component in a line, so "main", "universe", "restricted" and "multiverse" can be in a single line. Also note, Though you add more than one component in a single line, APT system considers them as separate line containing only one component.
So, If your sources.list
have a line like this
deb http://archive.ubuntu.com/ubuntu precise universe
Then it can't have another line like the below (which your files have)
deb http://archive.ubuntu.com/ubuntu precise main universe
which is equivalent of these two lines
deb http://archive.ubuntu.com/ubuntu precise main
deb http://archive.ubuntu.com/ubuntu precise universe
Because, you are duplicating universe twice, so there will be an error for that duplicate. An error will be given for each duplicate found.
Solution:
After analyzing your sources.list
file, I found that, It is a basic one which is supplied by Ubuntu by default. You can build a default file following the procedure:
-
Open a terminal and first rename the existing
sources.list
file tosources.list.bak
file. (we can safely remove that, but caution is good).sudo mv /etc/apt/sources.list /etc/apt/sources.list.bak
-
Then open
software-properties-gtk
to build a new one. Type the below command in a terminal or in dash command prompt with pressing Alt+F2software-properties-gtk
Note, for Ubuntu version 11.10 or earlier you have to use
gksu
before thesoftware-properties-gtk
command -
After the window is open,
- Select all four categories in Ubuntu Software tab
- Select precise-security, precise-updates and precise-backports category in Updates tab.
- Select Canonical partner and Independent category from Other software tab.
That's it. You have now a default sources.list
file without error. Compare this file with the previous one, if you want.
Update to deal with sources.list.d
dir's files
Sometimes a duplicate entry can be in a file in the /etc/apt/sources.list.d
directory, which is also used by APT. So, you should look at that directory and see if there is any duplicate in those files. It is not necessary for duplicates being in the same file.
Example case:
A user had this error message showing while doing sudo apt-get update
.
W: Duplicate sources.list entry http://dl.google.com/linux/chrome/deb/ stable/main amd64 Packages (/var/lib/apt/lists/dl.google.com_linux_chrome_deb_dists_stable_main_binary-amd64_Packages)
W: Duplicate sources.list entry http://dl.google.com/linux/chrome/deb/ stable/main i386 Packages (/var/lib/apt/lists/dl.google.com_linux_chrome_deb_dists_stable_main_binary-i386_Packages)
W: You may want to run apt-get update to correct these problems
But there was no entry with http://dl.google.com
in the main /etc/apt/sources.list
file. Looking at the /etc/apt/sources.list.d/
directory we found these files:
output of ls /etc/apt/sources.list.d/
:
aims-sagemath-precise.list
aims-sagemath-precise.list.save
dropbox.list
dropbox.list.save
fossfreedom-packagefixes-precise.list
fossfreedom-packagefixes-precise.list.save
google-chrome.list
google-chrome.list.save
google.list
google.list.save
sagemath-monolithic-precise.list
sagemath-monolithic-precise.list.save
The files google-chrome.list
and google.list
were good candidates for containing duplicates. So, checking the contents of both files was necessary.
Output of cat /etc/apt/sources.list.d/google-chrome.list
:
deb http://dl.google.com/linux/chrome/deb/ stable main
and of cat /etc/apt/sources.list.d/google.list
deb http://dl.google.com/linux/chrome/deb/ stable main
So, there was a duplicate entries in the sources of Apt. Since google-chrome.list
only contain a single apt line and it was also listed in google.list
file we can safely remove this file with the command
sudo rm /etc/apt/sources.list.d/google-chrome.list
Then the problem was solved.
For Ubuntu 12.04
Graphically:
Press Alt + F2 and paste software-properties-gtk
(or you can open "Software Center" then go to "Edit" > "Software Sources"). Go to tab "Other Software", choose the duplicate entry and press the "Remove" button.
If you need a command line option, here it is:
cat /etc/apt/sources.list | perl -ne '$H{$_}++ or print' > /tmp/sources.list && sudo mv /tmp/sources.list /etc/apt/sources.list
The command does this:
cat
reads the file and passes the content to perl
which removes the duplicate lines. The result is then saved >
in a temporary file which is then moved to replace the original /etc/apt/sources.list
file.
How bad are duplicate entries in sources.list?
I don’t know how bad it is, but i don’t like sudo apt-get update showing me duplicate entries.
By the way its not that bad, its just showing you that you have duplicate entries.
SourcesList
The sources.list file is a key factor in adding or upgrading applications to your Ubuntu installation. This is also used by your system for system updates. The file is basically the roadmap for your system to know where it may download programs for installation or upgrade.
Its just like Windows update
You can remove duplicate entries in few easy steps with Y PPA Manager
sudo add-apt-repository ppa:webupd8team/y-ppa-manager -y
sudo apt-get update
sudo apt-get install y-ppa-manager -y
Open y-ppa-manager form Dash
Enter You Admin Password
Double Click On Advanced
Scan & Remove Duplicate PPA's & Click Ok
It will take some time ( 1 or 2 Mints ) To Scan & Remove Duplicate PPA's