Re: [gentoo-portage-dev] Dynamic USE dependencies

[Kent Fredric]

On 3 April 2015 at 05:32, Rich Freeman <rich0@g.o> wrote:

> Out of curiosity, what is keeping us from having USE flag dependencies
> handled dynamically, in the same way that package dependencies are?
> If portage can figure out that I need libxml2 installed even if I
> don't put it in /var/lib/portage/world, why can't it figure out that I
> need it built with USE=icu even if I don't put that in
> /etc/portage/package.use?
>


I'd say its more a concept issue than an application issue.

USE flags often signify a need for code to be recompiled to grant the
feature.

How do you disambiguate between USE flags that *do* need a recompile to
enable their power, and those that *dont* need a recompile to enable their
power.

Or even clarify to portage that, "The older version of X that didn't have
IUSE=foo, actually had feature foo, but just didn't have the use flag" vs
"The older version of X that didn't have IUSE=foo, didnt have feature foo
or the IUSE".

Splitting this logic into an explicit bump kinda avoids the need for some
of these questions.

That last one however I'd like to see improved, because I often see new USE
flags turn up on packages, and I have no idea of knowing "Is this useflag
adding a feature, or exposing an existing one"

"Is this new useflag defaulted on because it already existed, or is it
defaulted on because its a new feature and its awesome"

"Is this new useflag defaulted off because it didnt already exist, or did
it exist and were disabling the feature because its bad"

.... Ad Infinitum.




-- 
Kent

*KENTNL* - https://metacpan.org/author/KENTNL