APT HOWTO
Chapter 7 - How to deal with errors

7.1 Common errors

Errors will always happen, many of them caused by users not paying attention. The following is a list of some of the most frequently reported errors and how to deal with them.

If you receive a message that looks like the one below when trying to run apt-get install package...

     Reading Package Lists... Done
     Building Dependency Tree... Done
     W: Couldn't stat source package list 'https://people.debian.org unstable/ Packages' (/var/state/apt/lists/people.debian.org_%7ekov_debian_unstable_Packages) - stat (2 No such file or directory)
     W: You may want to run apt-get update to correct these missing files
     E: Couldn't find package penguineyes

you forgot to run apt-get update after your last change to the /etc/apt/sources.list file.

If the error looked like:

     E: Could not open lock file /var/lib/dpkg/lock - open (13 Permission denied)
     E: Unable to lock the administration directory (/var/lib/dpkg/), are you root?

when trying any apt-get method other than source, you don't have root permission, that is, you're running as a normal user.

There's an error similar to the above which happens when you run two copies of apt-get at the same time, or even if you try to run apt-get while a dpkg process is active. The only method that can be used simultaneously with others is the source method.

If an installation breaks in the middle of the process and you find that it's no longer possible to install or remove packages, try running these two commands:

     # apt-get -f install
     # dpkg --configure -a

And then try again. It may be necessary to run the second of the above commands more than once. This is an important lesson for those adventurers who use `unstable'.

If you receive the error "E: Dynamic MMap ran out of room" when running apt-get update, add the following line to /etc/apt/apt.conf:

     APT::Cache-Limit 10000000;