On Sun, 12 Jun 2011 16:49:19 +0200
Ulrich Mueller <ulm@gentoo.org> wrote:
> >> It would be more accurate to say that it's guaranteed except for
> >> cases in which circular dependencies make it impossible to
> >> guarantee.
> 
> > This or other words, this makes this an unreliable feature. So,
> > right now, users can't assume anything specific about dependencies
> > being installed in pkg_*?
> 
> Currently, PMS only says: "These must be installed and usable before
> the ebuild is treated as usable." It doesn't say anything about
> phases.

The intention with the "usable" stuff is this that purely RDEPEND
cycles are resolvable, but any such cycles must be resolved before any
package which has a DEPEND upon anything in the cycle is resolved. So
if you've got this:

    first <-- rdepend --- second <-- depend --- third
          --- rdepend -->

Then (first, second, third) and (second, first, third) are the only
legal orderings. But if either RDEPEND became a DEPEND (and if we're
not dealing with binary packages) then there would be no legal ordering.

Whether or not what PMS says matches the intention is another matter...

-- 
Ciaran McCreesh