Re: [gentoo-dev] rfc: checking properties in ebuilds and eclasses

[William Hubbs]

On Mon, May 18, 2020 at 09:42:46PM +0200, Michał Górny wrote:
> Why would an ebuild have to check whether the ebuild is live?  Isn't it
> supposed to know that by definition?
 
 See below where I talk about the ebuild version.

> > The up side of this would be that we aren't reserving a specific version
> > number for live ebuilds.
>
> We aren't.

In practice we basically do. If an ebuild has version number 9999, that
version is considered a live ebuild.
 
 I suppose this brings up the question of one ebuild serving as release
 and live ebuilds.

I've written a number of ebuilds like this because it seems easier to
keep things in sync if you do this. I'm guessing others have done the
same also.

If I remember correctly you are not comfortable with ebuilds like this and I'm
not quite sure why.

> > The down side that is being pointed out to me right now is that
> > we would need a function like in_iuse, but called in_properties, to
> > check the properties. We would need something like this because
> > properties supports use conditionals, e.g.
> > PROPERTIES="foo? ( bar )"
>
> No, that's not why we needed in_iuse.  We need IUSE because IUSE is
> stacked and there's no guarantee that its value will be correct (or even
> present) at an arbitrary time during ebuild execution.
>
> in_iuse does not handle USE conditionals because obviously there are
> none in IUSE.
>
> PROPERTIES isn't stacked at the moment but there is a proposition to
> make it stacked in EAPI 8 for better consistency.  Right now it is easy
> to wrongly assume it is stacked and accidentally override it.

Is RESTRICT part of that proposal? It would be nice to have it
stacked as well.

Thanks,

William

>
> --
> Best regards,
> Michał Górny
>