Following steps 2-5 in the Package Manager Troubleshooting Procedure usually solves this problem.
For step 2, disable all your PPAs. You can uncheck all of them in Software Sources the same way you'd uncheck just one; see How to disable a particular PPA?. You can re-enable them later.
For step 3, close any open programs you can. It's probably safe to keep your web browser open so you have your instructions in front of you. But it's particularly important to make sure any package managers are not running. This include the Software Center, the Software Updater (Update Manager in older versions of Ubuntu), Synaptic, and Gdebi. It also includes command-line package management utilities like apt-get
, dpkg
, and aptitude
.
Note that if other users are logged on at the same time, they should log off if possible.
For step 4, open a terminal window. One way to do this that works no matter what desktop environment you use, is to press Ctrl+Alt+T.
For step 5, run these commands in the terminal window:
ubuntu-support-status
sudo grep -R proxy /etc/apt/*
grep proxy /etc/environment
echo $http_proxy
echo $ftp_proxy
grep proxy /etc/bash.bashrc
grep proxy ~/.bashrc
cat /etc/apt/apt.conf
sudo fuser -vvv /var/lib/dpkg/lock
sudo fuser -vvv /var/cache/apt/archives/lock
cat /etc/lsb-release
uname -a
sudo rm /var/lib/apt/lists/lock
sudo rm /var/cache/apt/archives/lock
sudo rm /var/lib/dpkg/lock
sudo cp -arf /var/lib/dpkg /var/lib/dpkg.backup
sudo mv /var/lib/dpkg/status /var/lib/dpkg/status-bad
sudo cp /var/lib/dpkg/status-old /var/lib/dpkg/status || sudo cp /var/backups/apt.extended_states.0 /var/lib/dpkg/status
sudo mv /var/lib/dpkg/available /var/lib/dpkg/available-bad
sudo cp /var/lib/dpkg/available-old /var/lib/dpkg/available
sudo rm -rf /var/lib/dpkg/updates/*
sudo rm -rf /var/lib/apt/lists
sudo rm /var/cache/apt/*.bin
sudo mkdir /var/lib/apt/lists
sudo mkdir /var/lib/apt/lists/partial
LANG=C;sudo apt-get clean
LANG=C;sudo apt-get autoclean
LANG=C;sudo apt-get --purge autoremove
LANG=C;sudo apt-get --fix-missing update -o APT::Cache-Limit=100000000
sudo dpkg --configure -a
sudo dpkg --clear-avail
LANG=C;sudo apt-get -f install
LANG=C;sudo apt-get --fix-missing install
LANG=C;sudo apt-get update -o APT::Cache-Limit=100000000 && sudo apt-get dist-upgrade
find /etc/apt -name '*.list' -exec bash -c 'echo -e "\n$1\n"; cat -n "$1"' _ '{}' \;
I copied that verbatim from PackageManagementTroubleshoootingProcedure on 2 March 2014. Those commands have evolved in the past and the recommended commands in that article may be changed or expanded on again in the future. So you may want to work from step 5 there. (That article, created/edited by "Contributors to the Ubuntu documentation wiki"--especially Mark Rijckenberg--is licensed CC-BY-SA 3.0, which allows inclusion here with proper attribution.)
Some of those commands attempt to fix the problem (and also may show diagnostic information); others display valuable information about the problem that you can include in your question or otherwise provide to someone helping you. (Or, depending on your skills, may enable you to diagnose and solve it.)
Often this fixes it but when it doesn't it often gives enough information to fix it.
You don't have to manually type those commands; you can copy and paste them. I recommend pasting and running each one separately, though. This makes it clearer what output is from which commands.