Re: [gentoo-dev] RFC: l10n.eclass

[Ciaran McCreesh]

On Fri, 20 Jul 2012 13:43:15 -0400
Alexandre Rostovtsev <tetromino@g.o> wrote:
> > If you dep upon foo[linguas_en(+)] and linguas_en isn't in IUSE,
> > what happens?
>
> Fatal error. If a package installs its translations implicitly via
> gettext's rules depending on the value of LINGUAS at configure time,
> then obviously other packages must rely on that package having
> installed any particular translation.

Uh, the entire point of the (+) is that it's *not* a fatal error if you
have a default.

> > > Otherwise, it is treated just like a normal environment variable,
> > > and portage doesn't touch it.
> >
> > It's not a normal environment variable, and it never has been.
>
> LINGUAS has been an environment variable with a special meaning for
> gettext-based build systems, which are rather popular in the free
> software world, since, oh, at least the year 2002 or so, when
> gettext-0.11 was released. Maybe even earlier.

And? Gentoo has decided to handle it otherwise.

> > > For most gettext packages, there is absolutely no reason that the
> > > ebuild maintainer should have to keep track of every translation
> > > available in a given package across version bumps. If you change
> > > this behavior in a future EAPI, you will break this.
> >
> > Don't use a USE_EXPAND variable if you don't want USE_EXPAND
> > behaviour.
>
> Thousands of packages rely on a particular interpretation of LINGUAS
> that has been standard across all distros for a decade. If that
> behavior changed in EAPI5, then EAPI5 is not suitable for adoption in
> Gentoo.

The feature was already approved by the Council for the EAPI originally
known as 3. It's necessary to make use dependency defaults work
correctly for USE_EXPAND variables (which they currently do not, due to
it being omitted from what became EAPI 4).

-- 
Ciaran McCreesh