[Buildroot] lua interpreter choice?

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Dear Danomi Manchego,

On Wed, 30 Jul 2014 14:51:49 -0400, Danomi Manchego wrote:

> > this change in the virtual-package behavior was introduced by
> > http://git.buildroot.net/buildroot/commit/?id=91169d3346e543be18139e18bdcc52a2345e0d16
> > (infra/pkg-virtual: validate only one provider provides an implementation)
> >
> > Fran?ois
> 
> But the menuconfig still lets you select both packages, instead of
> providing a choice of one or the other (like "jpeg support").  Is this
> not undesirable?

We discussed this before doing the commit pointed by Fran?ois.
Unfortunately, there's no good solution to solve this problem at the
kconfig level. The only solution would be to have each package being a
provider of a certain virtual package, have the knowledge of *all*
providers of that virtual packages to do a "depends
on !BR2_PACKAGE_<foo>". While for lua vs. luajit this seems more or
less reasonable, as we probably don't expect to have more providers
than just lua and luajit, but in the general case, we have things like
libgles or egl (for OpenGL support) which have multiple providers, and
we don't want to have to edit all of them whenever we add a new
provider.

Not speaking about packages in BR2_EXTERNAL, which we cannot control.

So our decision was to use a build-time check rather than a
kconfig-time check.

Hope this clarifies the situation,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com