Choosing default variant based on active variants of dependency

[Clemens Lang]

On Fri, Jan 03, 2014 at 02:19:30PM +0100, Mojca Miklavec wrote:
> Is there any simple way to write the port so that:
>     if (py*-wxpytho-2.8 is installed with +carbon) or
>         (py*-wxpython-2.8 is not installed and xcodeversion < 4.4) {
>         supported_archs i386
>     }
> 
> I could also add variants (+wxwidgets28 / +wxgtk28) if needed, but
> selecting the default variant should follow the same logic: if
> wxpython-2.8 is already installed, automatically choose the right
> variant. If it's not yet installed (but maybe that never happens -
> maybe it's always installed by the time this part of logic is
> executed), use the same strategy for selecting the default variant as
> for py-wxpython-2.8.

See the gobject-introspection port that changes its default variant
depending on whether you have python +ucs4 or not.

-- 
Clemens Lang