Re: [PATCH] debianize: introduce DEBIAN_PROVIDES and DEBIAN_REPLACES

[Uladzimir Bely <ubely@ilbers.de>]

On Tue, 2023-11-14 at 20:05 +0100, 'Cedric Hombourger' via isar-users
wrote:
> When optimizing an embedded system (and mostly for advanced users),
> dpkg-raw may be used to generate virtual packages to replace larger
> packages that would otherwise be pulled to satisfy image
> dependencies.
> 
> Signed-off-by: Cedric Hombourger <cedric.hombourger@siemens.com>
> ---
>  doc/user_manual.md             | 4 ++++
>  meta/classes/debianize.bbclass | 2 ++
>  2 files changed, 6 insertions(+)
> 
> diff --git a/doc/user_manual.md b/doc/user_manual.md
> index ecb987f4..0649ceeb 100644
> --- a/doc/user_manual.md
> +++ b/doc/user_manual.md
> @@ -906,6 +906,10 @@ For the variables please have a look at the
> previous example, the following new
>  Have a look at the `example-raw` recipe to get an idea how the
> `dpkg-raw` class can be used to customize your image.
>  Note that the package will be build using the whole debian package
> workflow, so your package will be checked by many debhelper scripts.
> If those helpers point out quality issues it might be a good idea to
> fix them. But `example-raw` also shows how rules can still be
> violated.
>  
> +Other (optional) customization variables include:
> + - `DEBIAN_PROVIDES` - declare a virtual package to satisfy
> dependencies
> + - `DEBIAN_REPLACES` - to replace a package with another
> +
>  ### Prebuilt .deb packages from somewhere
>  
>  In some cases you might find yourself having a `.deb` that someone
> else built,
> diff --git a/meta/classes/debianize.bbclass
> b/meta/classes/debianize.bbclass
> index 16f3638d..df7c5b50 100644
> --- a/meta/classes/debianize.bbclass
> +++ b/meta/classes/debianize.bbclass
> @@ -78,6 +78,8 @@ Package: ${BPN}
>  Architecture: ${DPKG_ARCH}
>  Depends: ${DEBIAN_DEPENDS}
>  Conflicts: ${DEBIAN_CONFLICTS}
> +Provides: ${DEBIAN_PROVIDES}
> +Replaces: ${DEBIAN_REPLACES}

Would not this somehow lead to broken control file if these new
variables are not defined / not used in the recipe? For other vars here
(e.g., DEBIAN_CONFLICTS, DEBIAN_DEPENDS) we at least have a weak
assignments (??= "") on top of debianize.bbclass.

>  Multi-Arch: ${DEBIAN_MULTI_ARCH}
>  Description: ${DESCRIPTION}
>  EOF
> -- 
> 2.39.2
>