Proposed Archive provides pre-released updates for Ubuntu, by default it’s not enabled. There may be bug fixes or new features in pre-released update packages and you can selectively upgrade them by enabling proposed archive.
Enable Proposed Archive in Ubuntu 12.04 (11.04 and higher):
Launch Ubuntu Software Center, go to Edit -> Software Sources -> Updates tab, check “Pre-released updates (precise-proposed)”
Install Packages from Proposed Archive:
After enabling proposed archive, configure apt to allow selective installs of packages from it instead of upgrading all of your packages to the -proposed versions.
Open up a terminal(Ctrl+Alt+T, or search from dash), run command to create and edit this file:
sudo gedit /etc/apt/preferences
copy and paste following into the file and save it. With this preference file in place, Update Manager, Synaptic and Aptitude won’t ask for upgrades from the -proposed repositories.
Pin: release a=precise-security
Pin: release a=precise-updates
Pin: release a=precise-proposed
Now, install aptitude by:
sudo apt-get install aptitude
Use aptitude to list and install updates from proposed archive.
sudo aptitude -t precise-proposed
In aptitude, you should first update the package listings (‘u’ key), mark any of the packages you want to upgrade (‘+’ key), and finally install them (‘g’ key). After this, if you run Aptitude without options again, the rest of precise-proposed upgradable packages will remain hidden.
Alternatively, you can install a package from -proposed by using
sudo aptitude install packagename/precise-proposed
It is recommend that you re-enable Apport bug filing to capture and report crashes. In the event that you end up reporting a crash about a proposed package please tag the bug as proposed-pkg so we can distinguish it from other crash reports.
You can enable Apport on a stable system with:
gconftool -s /apps/update-notifier/show_apport_crashes --type bool true
… or if you use Kubuntu edit /usr/share/kubuntu-default-settings/kde-profile/default/share/config/adept_notifierrc and set Addept=true: