Starting with Portage-2.3.8, a switch to a new repository configuration framework is complete and users may want to update their configuration files. This document aims to describe the goals for the new framework and how to use it.
Multiple repository layout
One of the most important changes is the switch from the old overlay layout to a new cleaner repository system. The new layout is more flexible and more predictable. For example, repositories can now use resources (eclasses, for example) provided by other repositories.
The old layout was based on the concept of one main tree and optionally a number of overlays. The main tree provided base system ebuilds, eclasses, profiles, while overlays mostly were able to provide their own ebuilds. The ebuild provided by overlays overrode the ebuilds in main tree to the extend of making it impossible to install the main tree version. Overlays could also provide eclasses for their own ebuilds and package.* entries that applied to all overlays and to the main tree. Over time, the old layout became less limiting and moved towards the new layout.
The new layout is based on the concept of one or more configurable repositories. Each repository can either be stand-alone or depend upon other repositories. The distribution provides a repository called funtoo (a drop-in replacement for Gentoo's gentoo repository). Users can install more repositories at they will, the repositories providing their own ebuilds, eclasses and profiles as necessary and/or using them from other repositories. Users can explicitly choose the repository they want to install packages from.