I keep getting this output when I run sudo apt-get update:  Err:1 http://security.ubuntu.com/ubuntu xenial-security InRelease   Temporary failure resolving 'security.ubuntu.com' Err:2 http://ppa.launchpad.net/certbot/certbot/ubuntu xenial InRelease   Temporary failure resolving 'ppa.launchpad.net' Err:3 http://et.archive.ubuntu.com/ubuntu xenial InRelease   Temporary failure resolving 'et.archive.ubuntu.com' Err:4 http://et.archive.ubuntu.com/ubuntu xenial-updates InRelease   Temporary failure resolving 'et.archive.ubuntu.com' Err:5 http://et.archive.ubuntu.com/ubuntu xenial-backports InRelease   Temporary failure resolving 'et.archive.ubuntu.com' Reading package lists... Done W: Failed to fetch http://et.archive.ubuntu.com/ubuntu/dists/xenial/InRelease  Temporary failure resolving 'et.archive.ubuntu.com' W: Failed to fetch http://et.archive.ubuntu.com/ubuntu/dists/xenial-updates/InRelease  Temporary failure resolving 'et.archive.ubuntu.com' W: Failed to fetch http://et.archive.ubuntu.com/ubuntu/dists/xenial-backports/InRelease  Temporary failure resolving 'et.archive.ubuntu.com' W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/xenial-security/InRelease  Temporary failure resolving 'security.ubuntu.com' W: Failed to fetch http://ppa.launchpad.net/certbot/certbot/ubuntu/dists/xenial/InRelease  Temporary failure resolving 'ppa.launchpad.net' W: Some index files failed to download. They have been ignored, or old ones used instead.   How this problem can be fixed?
12954
Err http://archive.canonical.com natty InRelease     Err http://security.ubuntu.com oneiric-security InRelease                Err http://extras.ubuntu.com natty InRelease                             Err http://security.ubuntu.com oneiric-security Release.gpg   Temporary failure resolving ‘security.ubuntu.com’ Err http://archive.canonical.com natty Release.gpg   Temporary failure resolving ‘archive.canonical.com’ Err http://extras.ubuntu.com natty Release.gpg   Temporary failure resolving ‘extras.ubuntu.com’ Err http://gb.archive.ubuntu.com oneiric InRelease Err http://gb.archive.ubuntu.com oneiric-updates InRelease Err http://gb.archive.ubuntu.com natty-backports InRelease Err http://gb.archive.ubuntu.com oneiric Release.gpg   Temporary failure resolving ‘gb.archive.ubuntu.com’ Err http://gb.archive.ubuntu.com oneiric-updates Release.gpg   Temporary failure resolving ‘gb.archive.ubuntu.com’ Err http://gb.archive.ubuntu.com natty-backports Release.gpg   Temporary failure resolving ‘gb.archive.ubuntu.com’  Reading package lists... Done W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric/InRelease       W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric-updates/InRelease   W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/natty-backports/InRelease   W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/oneiric-security/InRelease   W: Failed to fetch http://archive.canonical.com/ubuntu/dists/natty/InRelease   W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/natty/InRelease   W: Failed to fetch http://archive.canonical.com/ubuntu/dists/natty/Release.gpg  Temporary failure resolving ‘archive.canonical.com’ W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/oneiric-security/Release.gpg  Temporary failure resolving ‘security.ubuntu.com’ W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/natty/Release.gpg  Temporary failure resolving ‘extras.ubuntu.com’ W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric/Release.gpg  Temporary failure resolving ‘gb.archive.ubuntu.com’ W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric-updates/Release.gpg  Temporary failure resolving ‘gb.archive.ubuntu.com’ W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/natty-backports/Release.gpg  Temporary failure resolving ‘gb.archive.ubuntu.com’ W: Some index files failed to download. They have been ignored, or old ones used instead.   This is what I'm seeing when I try to run sudo apt-get update. I did an update on my instance yesterday and am now experiencing this.
114446
It is not unusual for an Ubuntu (or other distro with apt package management) user to encounter the error: user@box ~ $ sudo apt install x [sudo] password for user:  Reading package lists... Done Building dependency tree        Reading state information... Done Package x is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Package 'x' has no installation candidate  There have been several questions asked concerning this on various StackExchange sites,for example  on AskUbuntu, but these are generally about how to obtain the specific package despite the error. I have found no package that is not found simply (though not always easily) by determining if it is still distributed, and under which repository if so, and ensuring that repository is in apt.sources, or the worst comes to the worst downloading a .deb or source to compile. So my question is more general, and although I am guessing it has a rather simple and therefore non-exciting answer I cannot think how to find it by conventional search engine methods, so I turn to AskUbuntu: Is there a command or option I can use to determine what package / which packages reference the missing package?
17818
When I add a repository by running  sudo add-apt-repository ppa:ubuntu-x-swat/x-updates   It outputs this dialog:  Updated versions of X.org drivers, libraries, etc. for Ubuntu.  This PPA is for stable upstream releases of X.org components.  If you're looking for something even more bleeding-edge, please see the xorg-edgers PPA.  While Ubuntu does not "officially/formally" support these packages, if you discover problems when installing these debs please feel free to report bugs to launchpad.  However, please make sure to clearly state that you are running packages from this PPA so we know the fixes need to come here.  If you are upgrading from one release to another with this PPA activated, please install the ppa-purge package and use it to downgrade everything in here beforehand. sudo ppa-purge ppa:ubuntu-x-swat/x-updates will do it.  [Directions for packaging drivers can be seen at https://wiki.ubuntu.com/X/DriverBuilding]  More info: https://launchpad.net/~ubuntu-x-swat/+archive/x-updates Press [ENTER] to continue or ctrl-c to cancel adding it   I want to skip the confirmation step  Press [ENTER] to continue or ctrl-c to cancel adding it   How can I automatically confirm the addition of a PPA?
118143
After executing this command  sudo apt-get update &amp;&amp; sudo apt-get -y upgrade   I get this error  W: The repository 'http://dl.google.com/linux/chrome/deb stable Release' does not have a Release file. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details.   I've seen past inquiries on same issue but the answers given are specific to other repositories.  Any help will be appreciated.
28941
sudo apt-get upgrade installs all updates, not just security updates. I know that I can use Update Manager to select only important security updates, but is there a way to do this from the command line?
57501
Both apt-get update and upgrade hang:  sudo apt-get update [sudo] password for xxx:  0% [Connecting to archive.ubuntu.com (2001:67c:1360:8001::17)]   I'm able to ping archive.ubuntu.com:  ping archive.ubuntu.com PING archive.ubuntu.com (91.189.88.162) 56(84) bytes of data. 64 bytes from yukinko.canonical.com (91.189.88.162): icmp_seq=1 ttl=50 time=42.2 ms 64 bytes from yukinko.canonical.com (91.189.88.162): icmp_seq=2 ttl=50 time=42.1 ms 64 bytes from yukinko.canonical.com (91.189.88.162): icmp_seq=3 ttl=50 time=42.1 ms ^C --- archive.ubuntu.com ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2002ms rtt min/avg/max/mdev = 42.169/42.206/42.265/0.240 ms   I checked , and I don't think its the same issue.  Any tips for investigating this further?
10773
W: Invalid 'Date' entry in Release file /var/lib/apt/lists/_var_cuda-repo-8-0-local_Release N: Skipping acquire of configured file 'non-free/binary-arm64/Packages' as repository 'http://repository.spotify.com stable InRelease' doesn't support architecture 'arm64' E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial/main/binary-arm64/Packages  404  Not Found [IP: 91.189.88.161 80] E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-updates/main/binary-arm64/Packages  404  Not Found [IP: 91.189.88.161 80] E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-backports/main/binary-arm64/Packages  404  Not Found [IP: 91.189.88.161 80] E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-security/main/binary-arm64/Packages  404  Not Found [IP: 91.189.88.161 80] E: Some index files failed to download. They have been ignored, or old ones used instead.   After I installed Jetpack for Jetson tx1, my ubuntu constantly tries to fetch arm updates. Is there a way to disable this?  EDIT:   $dpkg --print-architecture amd64  $dpkg --print-foreign-architectures i386 arm64   I see that arm64 is included in foreign architectures. How do I remove it?
42223
So I am on my college network which requires me to sign in to the browser before I start using the internet. I do so succesfully but on a clean install of Ubuntu, when I try to do sudo apt update, I get the following output:  $ sudo apt update Get:1 http://in.archive.ubuntu.com/ubuntu xenial InRelease [2,847 B] Err:1 http://in.archive.ubuntu.com/ubuntu xenial InRelease                     Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?) Get:2 http://security.ubuntu.com/ubuntu xenial-security InRelease [2,854 B]     Err:2 http://security.ubuntu.com/ubuntu xenial-security InRelease              ... Get:3 http://in.archive.ubuntu.com/ubuntu xenial-updates InRelease [2,855 B]    Err:3 http://in.archive.ubuntu.com/ubuntu xenial-updates InRelease ... Get:4 http://in.archive.ubuntu.com/ubuntu xenial-backports InRelease [2,857 B] Err:4 http://in.archive.ubuntu.com/ubuntu xenial-backports InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?) Fetched 11.4 kB in 0s (18.3 kB/s) Reading package lists... Done E: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/xenial/InRelease  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?) ... E: Some index files failed to download. They have been ignored, or old ones used instead.   But when I do wget http://in.archive.ubuntu.com/ubuntu/dists/xenial/InRelease, I get this output success:  2017-04-01 05:34:57  http://in.archive.ubuntu.com/ubuntu/dists/xenial/InRelease Resolving in.archive.ubuntu.com (in.archive.ubuntu.com)... 91.189.88.162, 91.189.88.149, 91.189.88.152, ... Connecting to in.archive.ubuntu.com (in.archive.ubuntu.com)|91.189.88.162|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 246846 (241K) Saving to: ‘InRelease.3’  InRelease.3         100%[===================&gt;] 241.06K   110KB/s    in 2.2s      2017-04-01 05:35:00 (110 KB/s) - ‘InRelease.3’ saved [246846/246846]   Clearly I have internet access from my browser and on wget but when I do sudo apt (or apt-get) update I get this error.  PS: This question is not similar to other threads as their solutions do not seem to work on mine        As I have found out, this problem is happening only to me, not others on the college network. Despite setting up the network according to instructions, this still happens. Any more help would be appreciated  EDIT: So as it turns out, 50% of us in the college are facing this issue, while 50% aren't despite having no issues with the hardware and sudo apt update before the last week. Thanks to @David Foerster for helping me throughout all this time.  As it stands, the issue has been raised to our college's networking department :)
10743
For the last week or more, running sudo apt-get update culminates in error:  Reading package lists... Done E: Failed to fetch http://au.archive.ubuntu.com/ubuntu/dists/xenial/main/dep11/Components-amd64.yml   Could not open file /var/lib/apt/lists/partial/au.archive.ubuntu.com_ubuntu_dists_xenial_main_dep11_Components-amd64.yml.gz - open (13: Permission denied) [IP: 202.158.214.106 80] E: Failed to fetch http://au.archive.ubuntu.com/ubuntu/dists/xenial-backports/main/dep11/icons-64x64.tar  Could not open file /var/lib/apt/lists/partial/au.archive.ubuntu.com_ubuntu_dists_xenial-backports_main_dep11_icons-64x64.tar.gz - open (13: Permission denied) [IP: 202.158.214.106 80] E: Some index files failed to download. They have been ignored, or old ones used instead.   Entering either of the 2 specified urls into a browser address bar results in a 'File not found' (404) error - but if I append .gz to both addresses, then the respective files can be downloaded.  However, having downloaded the 2 files, I then don't know how (or if) I can utilize them.  Seeking advice on how best to proceed.
72965
Please let me know how to remove certain repositories in Ubuntu 11.04. I am getting the following errors while updating.  sudo apt-get update  Err http://ppa.launchpad.net natty/main Sources                                      404  Not Found Err http://ppa.launchpad.net natty/main i386 Packages                                404  Not Found ......  E: Some index files failed to download. They have been ignored, or old ones used instead.
119482
I have a local mirror (created with debmirror), and when I run apt-get update after a few days, I get this:  E: Release file expired, ignoring file:/home/wena/.repo_bin/dists/sid/Release (invalid since 14h 31min 45s)   How do I work around that?
84886
I searched and read all possible pages here but I could not find the exact problem.  When I open my terminal I am getting:  bash: /usr/bin/lesspipe: /bin/sh: bad interpreter: No such file or directory   then when I use apt-get update I am getting following errors.  Fetched 39,9 MB in 53s (747 kB/s)                                               Reading package lists. . .  Done W: GPG error: http://archive. canonical.com/ubuntu xenial InRelease: Could not execute 'apt-key' to verify signature (is gnupg installed?) W: The repository 'http://archive.canonical.com/ubuntu xenial InRelease' is not signed.  N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.  N: See apt-secure(8) manpage for repository creation and user configuration details.  W: GPG error: http://ppa.launchpad.net/nijel/phpmyadmin/ubuntu xenial InRelease: Could not execute 'apt-key' to verify signature (is gnupg installed?) ....... W: The repository 'http://us.archive.ubuntu.com/ubuntu xenial-security InRelease' is not signed.  N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.  N: See apt-secure(8) manpage for repository creation and user configuration details.  E: Problem executing scripts APT::Update::Post-Invoke-Success 'touch /var/lib/apt/periodic/update-success-stamp 2&gt;/dev/null || true' E: Sub-process returned an error code     $ namei -lx /bin/sh f: /bin/sh Drwxr-xr-x root root / drwxr-xr-x root root bin                      sh - No such file or directory   Does any one know why this error occurred and how can I solve it?
30485
When I do upgrade it gets stuck here:  user@plato:~# sudo apt-get upgrade Reading package lists... Done Building dependency tree        Reading state information... Done Calculating upgrade... Done The following packages will be upgraded:   bind9-host coreutils cpio curl dnsutils libbind9-90 libc-bin libc-dev-bin   libc6 libc6-dev libcgmanager0 libcurl3 libcurl3-gnutls libdns100   libdrm-intel1 libdrm-nouveau2 libdrm-radeon1 libdrm2 libisc95 libisccc90   libisccfg90 libjasper1 liblwres90 libplymouth2 libsepol1 libssl-dev   libssl-doc libssl1.0.0 linux-libc-dev mime-support multiarch-support ntp   ntpdate openssl plymouth plymouth-theme-ubuntu-text python3-distupgrade   ubuntu-release-upgrader-core unzip 39 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. Need to get 16.0 MB of archives. After this operation, 12.3 kB of additional disk space will be used. Do you want to continue? [Y/n] y 0% [Connecting to us.archive.ubuntu.com (2001:67c:1562::15)] ░   When I do update it gets stuck here:  user@plato:~# apt-get update 0% [Connecting to us.archive.ubuntu.com (2001:67c:1562::14)] [Connecting to sec░   I'm able to ping us.archive.ubuntu.com just fine:  user@plato:~# ping us.archive.ubuntu.com PING us.archive.ubuntu.com (91.189.91.23) 56(84) bytes of data. 64 bytes from economy.canonical.com (91.189.91.23): icmp_seq=1 ttl=54 time=81.5 ms 64 bytes from economy.canonical.com (91.189.91.23): icmp_seq=2 ttl=54 time=81.5 ms 64 bytes from economy.canonical.com (91.189.91.23): icmp_seq=3 ttl=54 time=81.5 ms 64 bytes from economy.canonical.com (91.189.91.23): icmp_seq=4 ttl=54 time=81.4 ms ^C --- us.archive.ubuntu.com ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 3004ms rtt min/avg/max/mdev = 81.425/81.528/81.582/0.355 ms   What can i do to fix this?    What I have tried so far.  I've tried following directions on this blog:   To force apt-get to use IPv4 exclusively   Create a file in /etc/apt/apt.conf.d/99force-ipv4 Add this line to newly created file Acquire::ForceIPv4 false; Apt-get will now use IPv4 exclusively
43213
When performing apt-get update, I get the following error:   root@ADS3-Debian6:/home/aluno# apt-get update Atingido http://sft.if.usp.br squeeze Release.gpg Ign http://sft.if.usp.br/debian/ squeeze/contrib Translation-en Ign http://sft.if.usp.br/debian/ squeeze/contrib Translation-pt Ign http://sft.if.usp.br/debian/ squeeze/contrib Translation-pt_BR   (...)  Obter:10 http://security.debian.org squeeze/updates/non-free i386 Packages [14 B] Baixados 612 kB em 4s (125 kB/s)                     Lendo listas de pacotes... Pronto There is no public key available for the following key IDs: 8B48AD6246925553
952
When updating, I get the following error message:   W: The repository 'http://ppa.launchpad.net/mc3man/trusty-media/ubuntu xenial Release' does not have a Release file.   Here, I find another statement on this error:   This recommends removing certain PPAs; and, I'm not sure if I should do that since it might mean not getting the updates that I need.    Is this what I should do?
104258
I'm trying to do an apt-get update or apt-get install xyz and I'm seeing timeouts like this:  W: Failed to fetch http://eu-west-1.ec2.archive.ubuntu.com/ubuntu/dists/oneiric-updates/Release.gpg   Unable to connect to eu-west-1.ec2.archive.ubuntu.com:http: [IP: 10.224.87.159 80]   Is this a transient issue with Ubuntu, or maybe it's something on my end. The box I'm accessing it from is in EC2-EU.  Perhaps there is a way to force the installer to use the US servers which seem to work?
86001
I got the following output every time I run apt-get update on my Debian 8.   Is there a way to fix this?   Err http://ppa.launchpad.net jessie/main amd64 Packages                         404  Not Found Ign http://ppa.launchpad.net jessie/main Translation-en                 Err http://ppa.launchpad.net jessie/main amd64 Packages                   404  Not Found Ign http://ppa.launchpad.net jessie/main Translation-en                 Fetched 164 kB in 3s (47.0 kB/s)                                        W: Failed to fetch http://ppa.launchpad.net/certbot/certbot/ubuntu/dists/jessie/main/binary-amd64/Packages  404  Not Found  W: Failed to fetch http://ppa.launchpad.net/ondrej/php/ubuntu/dists/jessie/main/binary-amd64/Packages  404  Not Found  E: Some index files failed to download. They have been ignored, or old ones used instead.   And this is what I have in /etc/apt/sources.list  deb http://ftp.debian.org/debian/ jessie main deb-src http://ftp.debian.org/debian/ jessie main  deb http://security.debian.org/ jessie/updates main deb-src http://security.debian.org/ jessie/updates main  # jessie-updates, previously known as 'volatile' deb http://ftp.debian.org/debian/ jessie-updates main deb-src http://ftp.debian.org/debian/ jessie-updates main  deb http://ftp.debian.org/debian jessie-backports main   And this is the output of cat /etc/apt/sources.list.d/*  deb http://ppa.launchpad.net/certbot/certbot/ubuntu jessie main # deb-src http://ppa.launchpad.net/certbot/certbot/ubuntu jessie main deb http://ppa.launchpad.net/ondrej/php/ubuntu jessie main # deb-src http://ppa.launchpad.net/ondrej/php/ubuntu jessie main deb http://ppa.launchpad.net/ondrej/php/ubuntu jessie main # deb-src http://ppa.launchpad.net/ondrej/php/ubuntu jessie main deb https://packages.sury.org/php/ jessie main deb https://packages.sury.org/php/ jessie main