Re: [bitbake-devel] [RFC] Proposal: New tool to display recipe dependency trees

On Mon, 24 Nov 2025 at 19:42, Osama Abdelkader
<[email protected]> wrote:

> My motivation actually was so simple, to know why a certain package is needed in an image.
> The simple way now AFAIK is to exclude it, then bitbake prints backtrace e.g.
>
> dnf
>  ├── libdnf
>  │    ├── libsolv
>  │    └── json-c
>  └── sqlite3
>
> dnf -> libdnf -> libsolv
>
> libsolv is needed for dnf. so would be good to have a query command or simple tool to show that?
> something like apt-rdepends output.

Yes, absolutely, and this is missing. You can deduce it from 'bitbake
-g', but it requires look at dependencies of particular tasks
(package_write_* if memory serves) and ignoring all other task
dependencies, and then making a mental dependency chain in your head
if the dependency is indirect. This could probably be post-processed
with some filtering tool to only make a tree of those dependencies,
and present it in a human friendly tree format.

One other idea is to add a task to image recipes that would produce a
tree of package dependencies. E.g. instead of making a package repo
and then constructing a root filesystem from it with a package
manager, it would use the repo to write out a tree of their
dependencies - unrolling the top level packages that the image
specifies to install. Probably it could use package managers like
dnf/apt/opkg to assist with that.

Alex