78 votes

How do I change mirrors in Ubuntu Server from regional to main?

This command should do the trick: sudo sed -i 's|http://us.|http://|g' /etc/apt/sources.list It will remove the 'us.' prefix in each of the addresses to convert them to addresses of the main server. ...
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59 votes

GPG ERROR NO_PUBKEY : WARNING: The following packages cannot be authenticated!

Run command: sudo apt-get update For every 16-character key that is reported as missing, run the following with the key substituted: sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys ...
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  • 8,706
54 votes

How do I enable the "multiverse" repository?

Another option available for newer releases of Ubuntu: sudo apt-add-repository multiverse && sudo apt-get update From the man page: Examples: apt-add-repository 'deb http://myserver/path/...
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35 votes

How do I restore the default repositories?

By default there will be a backup for your sources.list file on the same directory itself. sudo cp /etc/apt/sources.list.save /etc/apt/sources.list Answer from similar question here: What is the ...
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32 votes

A "failed to fetch" error occurs when apt-get update is run. How do I fix this?

I was facing the same problem and figured the easiest solution is to reset the sources of /etc/apt/sources.list. To do so, follow these steps: Obtain the release of your Ubuntu version, type into the ...
27 votes
Accepted

list.save and list.distUpgrade

I am not sure about sources.list.distUpgrade, but the sources.list.save file is a backup of the sources.list file. I know from personal experience (about 5 minutes ago) that the sources.list.save ...
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  • 1,930
24 votes

signature verification error for wine - index files failed to download - changing mirror doesn't help

As of 2018-12-19 08:07 there is a new winehq.key keyfile as mentioned here. Download the new repository key and add it to the list of trusted keys: cd /tmp wget -nc https://dl.winehq.org/wine-builds/...
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  • 371
22 votes

difference between sources.list and sources.list.distUpgrade

When you upgrade between distro versions, .list files in /etc/apt/sources.list.d get commented out. The original versions of those files get backed up with the .distUpgrade extension, and that's what ...
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22 votes
Accepted

signature verification error for wine - index files failed to download - changing mirror doesn't help

Note that after adding the new keyfile, it is better to use apt update rather than apt-get update, as it will prompt you to accept the changes. So in full: wget -nc https://dl.winehq.org/wine-builds/...
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  • 384
21 votes

How to install rar (no installation candidate)?

Install with the following commands, sudo apt-get install unrar-free
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21 votes
Accepted

What is apt-file update?

apt-file is used to do a search of which package provides a file. Consider it the offline and somewhat limited version of http://packages.ubuntu.com. Since you used apt-file update without sudo, it ...
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  • 184k
21 votes
Accepted

Ubuntu 16.04 - sudo apt-get update error

First, you need to edit or create your /etc/apt/sources.list file so run the following command: sudo nano /etc/apt/sources.list Now, copy and paste the following contents into the terminal: # deb ...
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  • 39k
20 votes
Accepted

Can there be any issue if I edit sources.list and jump between Ubuntu releases?

Congratulations, you have discovered the original Debian method of migrating between Debian releases: editing sources and then running dist-upgrade. The Ubuntu do-release-upgrade method uses dist-...
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  • 40.6k
19 votes
Accepted

The new software center in Ubuntu 16.04 shows no application data found

Just had this problem after using bleachbit to cleanup the system on moving from the beta to the official release. Cleaning out all the cache data also blanked out the software center (re:user533424 ...
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  • 206
19 votes
Accepted

Why is some software not in the official Ubuntu repositories?

Software in main is supported by Canonical. Obviously they're not going to support every arbitrary piece of software on the internet. Software in universe is inherited from Debian, where a select ...
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  • 184k
17 votes
Accepted

Limit apt repo to a certain arch?

From man sources.list: The format for a sources.list entry using the deb and deb-src types is: deb [ options ] uri suite [component1] [component2] [...] ... options is always optional and needs ...
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  • 184k
16 votes
Accepted

How to know the path of a particular software?

Find the path of an executable Best way type executable Check out this question to learn more about how type is better. (Thanks, comments!) Other ways whereis executable which executable Those ...
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  • 565
15 votes
Accepted

Updated Ubuntu 16.04, now I'm running Kali?

Yes, you are now using Kali. I consider this far too destructive and I would file a bug report for this if I was you. Our upgrade should not upgrade you to another (aka. unsupported by Canonical) ...
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  • 279k
15 votes
Accepted

How can PPAs be removed using GUI?

Remove PPAs with Ubuntu 16.04 LTS GUI Select Software Settings -> Software & Updates -> Other Software: Highlight the PPA you want to remove and click the Remove button. Note that many PPA'...
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15 votes

How to install Zoom for online meeting?

I've been using Zoom on Ubuntu using the official .deb file downloaded from their site. However, the latest update (Version 5.1.412382.0614) made things look ugly (huge icons, low-res, etc) and behave ...
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  • 14.6k
14 votes
Accepted

Can I install Kali tools on Ubuntu?

The only current version of Ubuntu this works for is 12.04 and the repos haven't been updated since 2013. Don't use it. For 14.04+, please see the second answer. Copy the following Kali repositories: ...
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13 votes
Accepted

apt build-dep fails, unable to locate source package, despite deb-src lines present in the /etc/apt/sources.list.d folder

You need to uncomment the deb-src lines in the main sources file /etc/apt/sources.list, not the extra files in /etc/apt/sources.list.d For example, change: # See http://help.ubuntu.com/community/...
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  • 67k
13 votes
Accepted

What is "deb deb-src stable/xenial main" in /etc/apt/sources.list

Your question revolves around the syntax or format of source list file that describes other programs what, how & from where to get the sources. So, Here it goes : Apt ( Advanced package tool ) ...
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  • 2,057
13 votes

Is editing sources.list a good idea?

Editing /etc/sources.list is one step to migrate to a subsequent release in Debian...but not in Ubuntu. You can still use it, but it's not recommended because most users shouldn't need to deal with ...
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  • 40.6k
12 votes

How do I enable the "partner" repository?

CLI method This method uses lsb_release -sc to get the Ubuntu (codename) version. add-apt-repository to alter the appropriate config files. It has the advantages of working in all versions of ...
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  • 409
12 votes
Accepted

How to List all software installed on Ubuntu 14.04 and Uninstall them

Open up a terminal and type, $ dpkg --list to list all the installed packages. To completely remove the package you want, type: $ sudo apt-get purge <package_name> For example, $ sudo ...
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  • 448
12 votes

The new software center in Ubuntu 16.04 shows no application data found

Happenes after you used BleachBit with root access and cleaned App cache Data Open Ubuntu Software Center Click on updates tab Click on small refresh button located at the top-left corner Wait for ...
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12 votes

what is the default content of /etc/apt/sources.list in Ubuntu 18.04 LTS (Bionic Beaver)

As you just want to remove unneeded lines from your sources.list, below is an example of what you could have in the contents of your file: deb http://in.archive.ubuntu.com/ubuntu/ bionic main ...
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  • 5,763
12 votes

No updates for 4 months on Ubuntu 20.04 LTS

Seems like an issue with the repositories. Check if your mirror is up to date. Then follow these steps: Open Software and Updates app. sudo software-properties-gtk As you want ALL the upgrades, I ...
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  • 5,102
11 votes

How do I enable the source code repositories?

You can enable source code repositories by uncommenting (removing #'s) deb-src repositories from /etc/apt/sources.list. sed -i '/deb-src/s/^# //' /etc/apt/sources.list && apt update If you ...
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  • 223

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