gnome-session-fallback software package provides GNOME Session Manager - GNOME fallback session, you can install in your Ubuntu 12.04 LTS (Precise Pangolin) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install gnome-session-fallback
gnome-session-fallback is installed in your system.
Make ensure the gnome-session-fallback package were installed using the commands given below,
$ sudo dpkg-query -l | grep gnome-session-fallback *
You will get with gnome-session-fallback package name, version, architecture and description in a table
| Distro | Ubuntu 12 04 lts precise pangolin |
| Section | GNOME |
| Package | gnome-session-fallback |
| Version | 3.2.1-0ubuntu8 |
| Description | GNOME Session Manager - GNOME fallback session |
| Sub Section | GNOME |