Re: [gentoo-dev] Adding USE=udev to linux profiles

[Rich Freeman]

On Tue, Jul 24, 2018 at 5:11 PM Dennis Schridde <devurandom@×××.net> wrote:
>
> On Tuesday, 24 July 2018 20:57:09 CEST Rich Freeman wrote:
> > On Tue, Jul 24, 2018 at 2:32 PM Ian Stakenvicius <axs@g.o> wrote:
> > > I don't think the process needs to be simplified much more than this;
> > > each layer above has its purpose.  However I do very much want to
> > > caution on making it more complicated, especially with the addition of
> > > syntax that allows setting or ignoring useflag state changes in a way
> > > that will jumble up these layers.
> >
> > I think as long as it is a heirarchy it will be straightforward enough.
> >
> > If we introduce a ^ operator that unsets a flag, the only question is
> > how far that propagates down the layers, and into what kinds of
> > layers:
> >
> > Does a profile ^flag undo an IUSE +flag?
> > Does a make.conf ^flag undo a profile +flag?  An IUSE +flag?  A
> > profile flag mask?
> > Does a package.use ^flag undo a make.conf +flag?  A profile +flag, an
> > IUSE +flag?  Etc...
>
> I guess the question here is: Is there an official order in which the use
> settings from the different profiles and config files have to be applied?
>
> I think my initial assumption of this order was wrong, USE flags only have two
> states and indeed it seems that the ^ USE operator is not necessary, because
> the - operator already serves the same purpose.
>

Kinda sorta.  In the flag is either set or it isn't.  However, I think
the intent here was to strip out the effects of profiles, but keep the
effects of IUSE.  The question then becomes what other contexts can it
be used in, and in each case what does it undo?

-- 
Rich