RE: [oe] Depending on other package's features.

[Peter Kjellerstedt <peter.kjellerstedt@axis.com>]

> -----Original Message-----
> From: openembedded-devel@lists.openembedded.org <openembedded-
> devel@lists.openembedded.org> On Behalf Of Maxim Sloyko via
> lists.openembedded.org
> Sent: den 4 november 2021 22:46
> To: openembedded-devel <openembedded-devel@lists.openembedded.org>
> Subject: [oe] Depending on other package's features.

This type of questions belong on the 
openembedded-core@lists.openembedded.org mailing list.

> 
> Hi all,
> 
> The recipe that I'm working on for our system (let's call it A) has a
> dependency on a certain feature being enabled in another package (B).
> So, in B, we have:
> 
> PACKAGECONFIG[nice-feature] = "..."
> 
> and my recipe (or rather, the tool built by the recipe), needs that
> feature to be enabled to work properly. What's worse, is that this is
> a runtime dependency, so if somebody just forgets to enable that
> feature, the image will build fine, but the tool won't work. I would
> like this to be a build time failure.
> 
> My plan is to change recipe A, so that if the "nice-feature" is
> enabled, the package will PROVIDE one more thing:
> 
> PROVIDES += "${PN}-nice-feature"
> 
> and in my recipe B, I'll declare this as a dependency:
> 
> RDEPENDS:${PN} += "package-a-nice-feature".

PROVIDES is for build time provides of recipes. You cannot mix it 
with RDEPENDS:${PN} which is for runtime dependencies for packages.

> Now I'm thinking, wouldn't it be great if package A could specify
> extra PROVIDES when the feature is configured? This would be similar
> to the way it's done for package's R?DEPENDS:
> 
>      PACKAGECONFIG ??= "f1 f2 f3 ..."
>      PACKAGECONFIG[f1] = "\
>                           --with-f1, \
>                           --without-f1, \
>                           build-deps-for-f1, \
>                           runtime-deps-for-f1, \
>                           runtime-recommends-for-f1, \
>                           packageconfig-conflicts-for-f1 \
>                           provides-for-f1 \
>                           "
> 
> The last line would be a change that I propose. It looks like it would
> be relatively easy to implement this in base.bbclass
> 
> What do you think? Will this be useful? Did I miss an existing way to do
> this?
> 
> Thanks,
> 
> --
> -MS

//Peter