On Fri, Nov 5, 2021 at 3:25 PM Maxim Sloyko via lists.openembedded.org
<maxims=google.com@...> wrote:

Hi all,

Posting this to openembedded-core, as it was suggested to me.

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".

You're doing that just to generate a build time error if the two
recipe's configurations are not consistent?

The normal approach would be to define a global variable (e.g. a
distro feature) which both recipes can check and use to configure
themselves appropriately.

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