Re: [gentoo-portage-dev] Try to specify how to get that a USE flag is present in current ebuild

[Pacho Ramos]

El vie, 21-09-2012 a las 12:45 -0700, Zac Medico escribió:
> On 09/21/2012 12:08 PM, Pacho Ramos wrote:
> > Hello
> >
> > This comes from this gentoo-dev thread:
> > http://www.gossamer-threads.com/lists/gentoo/dev/260536
> >
> > In that one, we try to use the following:
> > has vala ${IUSE//+/} && ! use vala && return 0
> >
> > as already done in many eclasses/ebuilds. The problem is that Ciaran
> > wants to forbid it because he says it's not specified in PMS. My
> > suggestion was to simply specify it as it's currently implemented in
> > portage because that functionality is (apart of needed) being used for a
> > long time in the tree by numerous eclasses/ebuilds, then, from my point
> > of view, wouldn't be any sense on lose time for moving them to current
> > functionality to a worse one, wait for the next eapi and, finally,
> > revert them back to current behavior.
> >
> > The problem is that I cannot find any doc about how this is currently
> > handled in portage. Could you help me on it please?
>
> That `has vala ${IUSE//+/}` thing should work for all versions of
> portage that have existed since PMS came around. The way that it works
> is that that ebuild.sh sources the ebuild, and the inherit function
> makes temporary backups of IUSE so that the IUSE settings from all of
> the eclasses and the ebuild can be stacked together after the sourcing
> is complete. The stacked IUSE value that's generated then remains in the
> ebuild's environment for all phases.

Thanks a lot, do you let me send your reply to gentoo-dev ML?