I am currently running Ubuntu 12.04. I intend to do so for the future because of its long time support and stability. However, I would like to contribute to testing proposed updates for Precise. I know that the proposed updates can be enabled through software sources. However doing so will install all proposed updates. However, I would like to test only a specific package (unity) and its dependencies.
How would I go about doing this?
Yes, this can be controlled by 'pinning' the release channel priorities. See this how to on how to configure APT to do this by setting pin-priorities on release channels.
The specific number set there is the key. High enough to receive updates when installed from the channel, yet low enough to get installed by default when not selecting the specific channel.
Then use your package management to select the release channel like this:
The how-to I just mentioned is using
aptitude
, but I recommend apt-get in recent Ubuntu versions as it has trouble handling multiarch dependencies, in my experience.