> 2. The second guide uses a lot of "one-shot" emerges; could anyone > please explain why I'd use a one-shot? > > ISTM that if a package is on my system, I'd want it routinely updated. > If I need it only once, then instruct me to unmerge it after it's done!? > > The basic idea of --oneshot is to avoid recording in the portage world file. So, for example, you want xorg and some other things in world. This will call in the dependencies. However, for major upgrades, my experience with other packages is that sometimes it's better to pull some new dependencies in first, then install the update. In principle, portage should take care of all this, but portage isn't always perfect. I'd guess this is the reason for --oneshot on some new xorg dependencies. They'll be called in on updates via dependencies, but this is a better way to proceed for updating from a lower version. Maybe on a newer version of xorg, these dependencies won't be required (unlikely, but possible), and thus you can avoid putting them explicitly in world.
~daid
