Re: [PATCH] navit: enable qml build

[Martin Jansa <martin.jansa@gmail.com>]

On Fri, Jun 11, 2010 at 01:53:36PM +0800, Holger Freyther wrote:
> On 06/11/2010 04:07 AM, Martin Jansa wrote:
> > * but for now without DEPENDS on qt4-x11-free, because 4.7.0 is not yet
> >   released and building qt4-x11-free just because of navit (for someone
> >   not using it for something else) takes a lot of time
> 
> I might not understand everything here, but this looks dangerous. A
> package rebuild should always generate the same kind of package.

Yes it's dangerous indeed.

Python DEPENDS contains 
${@base_contains('DISTRO_FEATURES', 'tk', 'tk', '', d)}

Then it's ensured that if you have tk in DISTRO_FEATURES then it's
picked by automatic in do_configure. But if you don't have it in
DISTRO_FEATURES then it depends if you build something depending on tk
before trying to build python or not. Even worse case is when you build
an image (ie kernel, python (without tk), th, something_depending_on_tk)
and then someone PR bump python and now you'll get python with tk).

I guess there is plenty of examples where configure has "automatic" by
default and we don't DEPEND on optional stuff and also don't force it
with --disable-some-optional-feature :/.

I think that best solution would be something like
DEPENDS += "${@base_contains('DISTRO_FEATURES', 'qt', 'qt4-x11-free', '', d)}"
EXTRA_OECONF += "${@base_contains('DISTRO_FEATURES', 'qt', '--enable-gui-qml', '--disable-gui-qml', d)}"

which is not so common in OE AFAIK and looks like how USE flags are
handled in gentoo (but they have better syntax to make it shorter).

Regards,

-- 
Jansa 'JaMa' Martin     jabber: Martin.Jansa@gmail.com