I've slowly been working on creating an x86 OpenBSD-based flavor of gentoo, and my first step was to create an "x86obsd" keyword. As drobbins has pointed out, if we really get rolling on this project we could have an explosion of arch*flavor*userland keywords, which would be _really_ ugly. Drobbins has suggested a new "userland/arch" format for keywords, and Method has pointed out that the even that may not be sufficient, as we should really have flags for arch, libc, and userland (since it is possible to have a GNU userland running on a system w/ a BSD kernel and either a BSD or a GNU libc). I don't have a good solution at the moment, but I'm opening this bug so that it doesn't get lost. Reproducible: Always Steps to Reproduce: 1. 2. 3.
Lets not forget Solaris, that is what I'm working on right now, getting portage going under Solaris. After that I planned on trying my hand at Irix. I had this same idea that the arch and os should be separate variables.
Whoops, never got around to closing this bug. See GLEP 22.