Re: [PATCH 2/2] docs: changes: better document Python needs

[Akira Yokosawa <akiyks@gmail.com>]

[+CC Laurent and Jani]

Hi,

On Mon, 28 Jul 2025 16:54:29 +0200, Mauro Carvalho Chehab wrote:
> Python is listed as an optional dependency, but this is not
> true, as:
> 
> 1) CONFIG_LTO_CLANG runs a python script at scripts/Makefile.vmlinux_o;
> 
> 2) kernel-doc is called during compilation when some DRM options
>    like CONFIG_DRM_I915_WERROR are enabled;
> 
> 3) allyesconfig/allmodconfig will enable both.

Well, these conditions still sound to me optional.

> 
> So, better document that.
> 
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> ---
>  Documentation/process/changes.rst | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst
> index bccfa19b45df..f6abecf6da86 100644
> --- a/Documentation/process/changes.rst
> +++ b/Documentation/process/changes.rst
> @@ -61,7 +61,7 @@ Sphinx\ [#f1]_         3.4.3            sphinx-build --version
>  GNU tar                1.28             tar --version
>  gtags (optional)       6.6.5            gtags --version
>  mkimage (optional)     2017.01          mkimage --version
> -Python (optional)      3.9.x            python3 --version
> +Python                 3.9.x            python3 --version
>  GNU AWK (optional)     5.1.0            gawk --version
>  ====================== ===============  ========================================
>  
> @@ -154,6 +154,17 @@ Perl
>  You will need perl 5 and the following modules: ``Getopt::Long``,
>  ``Getopt::Std``, ``File::Basename``, and ``File::Find`` to build the kernel.
>  
> +Python
> +------
> +
> +CONFIG_LTO_CLANG requires python 2.7 or 3.0+; some DRM config options like
> +CONFIG_DRM_I915_WERROR require at least Python 2.7 or 3.4+.
> +
> +The kernel-doc tool and docs build require at least 3.6, but they depend on
> +dict changes that happened on 3.7 to produce valid results.
> +
> +Other tools within the Kernel tree require newer versions.
> +

These details look confusing in changes.rst.  The table above says
python >=3.9.x.  All you need to say here would just something lile:

+Python
+------
+
+Required with CONFIG_LTO_CLANG, some DRM config options like
+CONFIG_DRM_I915_WERROR, the kernel-doc tool, and docs build (Sphinx),
+among others.

Other details can go to comments in each script or other docs if
necessary.

        Thanks, Akira