Re: [gentoo-dev] GLEP: gentoo sync based unified deps proposal

[Michał Górny]

On Tue, 18 Sep 2012 23:06:19 +0100
Ciaran McCreesh <ciaran.mccreesh@××××××××××.com> wrote:

> On Wed, 19 Sep 2012 00:01:21 +0200
> Michał Górny <mgorny@g.o> wrote:
> > On Tue, 18 Sep 2012 22:37:19 +0100
> > Ciaran McCreesh <ciaran.mccreesh@××××××××××.com> wrote:
> > > On Tue, 18 Sep 2012 23:34:29 +0200
> > > Michał Górny <mgorny@g.o> wrote:
> > > > On Tue, 18 Sep 2012 22:08:43 +0100
> > > > Ciaran McCreesh <ciaran.mccreesh@××××××××××.com> wrote:
> > > > > On Tue, 18 Sep 2012 23:06:06 +0200
> > > > > Michał Górny <mgorny@g.o> wrote:
> > > > > > But didn't we already point out that we can't have them in
> > > > > > RDEPEND since they introduce conflicts?
> > > > >
> > > > > You are missing a basic and important part of how dependency
> > > > > resolution works: currently, cycles consisting purely of
> > > > > RDEPENDs are ignorable.
> > > >
> > > > So, what do we lose? If PDEP comes 'ASAP' officially, I believe
> > > > that we actually gain RDEPs which can be actually trusted.
> > >
> > > "ASAP" is a weaker guarantee that RDEPENDs currently have --
> > > RDEPENDs currently have the weakest guarantee necessary to ensure
> > > that they can be trusted. It's also a useless guarantee, since
> > > "ASAP" can be arbitrarily late.
> >
> > And can't RDEPENDs be arbitrarily late if there is a cycle?
>
> No. RDEPENDs have to be available when a package is used to satisfy a
> dependency. That's the difference between an RDEPEND and a PDEPEND.

So, if a particular cycle prohibits RDEPENDs being fulfilled when
RDEPEND is needed to satisfy a dependency, we have a failure now,
correct?

Do we have that guarantee somewhere in the PMS?

-- 
Best regards,
Michał Górny