Subject: Re: [PATCH v2 3/3] b4: introduce configuration for the Git project

From: Toon Claes <[email-masked]>
Date: Wed, 03 Jun 2026 15:58:38 +0200

Patrick Steinhardt <[email-masked]> writes:

> We're about to extend our documentation to recommend b4 for sending
> patch series to the mailing list. Prepare for this by introducing a b4
> configuration so that the tool knows to honor our preferences. For now,
> this configuration does two things:
>
>   - It configures "send-same-thread = shallow", which tells b4 to always
>     send subsequent versions of the same patch series as a reply to the
>     cover letter of the first version.
>
>   - It configures "prep-cover-template", which tells b4 to use a custom
>     template for the cover letter. The most important change compared to
>     the default template is that our custom template also includes a
>     range-diff.
>
> There's potentially more things that we may want to configure going
> forward, like for example auto-configuration of folks to Cc on certain
> patches. But these two tweaks feel like a good place to start.
>
> Note that these values only serve as defaults, and users may want to
> tweak those defaults based on their own preference. Luckily, users can
> do that without having to touch `.b4-config` at all, as b4 allows them
> to override values via Git configuration:
>
>     ```
>     $ git config set b4.prep-cover-template /does/not/exist
>     $ b4 send --dry-run
>     ERROR: prep-cover-template says to use x, but it does not exist
>     ```
>
> So this gives users an easy way to override our defaults without having
> to touch ".b4-config", which would dirty the tree.
>
> Signed-off-by: Patrick Steinhardt <[email-masked]>
> ---
>  .b4-config         |  6 ++++++
>  .b4-cover-template | 11 +++++++++++
>  2 files changed, 17 insertions(+)
>
> diff --git a/.b4-config b/.b4-config
> new file mode 100644
> index 0000000000..fd4fb56b6d
> --- /dev/null
> +++ b/.b4-config
> @@ -0,0 +1,6 @@
> +# Note that these are default values that you can tweak via the typical
> +# git-config(1) machinery. You thus shouldn't ever have to change this file.
> +# See also https://b4.docs.kernel.org/en/latest/config.html.
> +[b4]
> +send-same-thread = shallow

Is it worth to note this requires v0.15 or higher?

That version was released only 2 months ago, I can imagine many distros
still ship an older version, what happens if a version doesn't support
this setting yet?

> +prep-cover-template = ./.b4-cover-template
> diff --git a/.b4-cover-template b/.b4-cover-template
> new file mode 100644
> index 0000000000..ab864933b5
> --- /dev/null
> +++ b/.b4-cover-template
> @@ -0,0 +1,11 @@
> +${cover}
> +
> +---
> +${shortlog}
> +
> +${diffstat}
> +
> +${range_diff}
> +---
> +base-commit: ${base_commit}
> +${prerequisites}
>
> -- 
> 2.54.0.1064.gd145956f57.dirty
>
>

-- 
Cheers,
Toon