Unity JHBuild is not intended for people that simply want to try out Unity. Unity JHBuild is primarily for developers that have a need for working across a full bleeding edge stand alone Unity stack without hosing their system.

If you are not familiar with working in a command line environment and debugging build issues Unity JHBuild is not for you.

If you have questions regarding unity-jhbuild you can drop in on #ayatana IRC-channel on FreeNode or mail directly to mikkel.kamstrup canonical.com