Fix dpkg available file in Ubuntu

This note relates to Ubuntu Maverick Meerkat (10.10) but it might apply to other versions, as well.

I wrote this note after my system became unstable following a number of configuration shenanigans. What did not help is that I had just upgraded from 10.04 to 10.10. Therefore, I am not sure that I can explain how to get to the state my platform was in.

Symptom: Every time an apt-get command is run, some sort of error or warning is reported stating that an available package has a corrupt version number.

Cause: The ‘available’ file used by dpkg contains erroneous information or is corrupted.

Solution: Rebuild the ‘available’ file.

Recipe:

1. Back up current file

2. Delete current ‘available’ file

3. Rebuild ‘available’ file

After these steps, commands to ‘apt-get’ should no longer complain about available versions.

Re-install GNOME-Session in Ubuntu

This note was written while using Ubuntu 10.10. However, it might apply to other versions as well.

Symptoms: After a number of shenanigans involving configuration, I found myself unable to login to the desktop, in Ubuntu. The login screen (GDM) offered my user name. However, once my user name was selected, no session were offered. Entering my password and pressing the login button would show a brief blank screen and then return me to the login screen.

Cause: Somehow, the gnome-session was removed from installation.

Solution: Re-install gnome-session

Here is the recipe:

  1. At the login screen (GDM), press the key combination CTL-ALT-F1. This should drop you out of GDM and into a terminal screen
  2. Login to the terminal using your username and password
  3. At the prompt, enter the command “sudo apt-get install gnome-session”
  4. Then, “sudo reboot”

If the gnome-session was already installed and you get an error attempting to install it again (or the answer “gnome-session is already installed”), then reconfiguring it might suffice: “sudo dpkg-reconfigure gnome-session”