Re: [PATCH] Updates Documentation/Makefile to use Python3 as fallback

[Masahiro Yamada <masahiroy@kernel.org>]

On Sat, Jan 30, 2021 at 9:15 AM Jonathan Corbet <corbet@lwn.net> wrote:
>
> Noa Sakurajin <noasakurajin@web.de> writes:
>
> [CC += kbuild maintainers]
>
> >  Before the command python was needed for the documentation to build.
> >  This patch checks if python is available and uses python3 as
> >  fallback.
> >
> >  This is needed because a lot of distribution (at least Ubuntu)
> >  only provide python3 and not python. scripts/sphinx-pre-install
> >  checks for python3 first and does not check if python exists
> >  which causes it to report that everything is installed even
> >  if the documentation build failed.
> >
> > Signed-off-by: Noa Sakurajin <noasakurajin@web.de>
> > ---
> >  Documentation/Makefile | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/Makefile b/Documentation/Makefile
> > index 61a7310b49e0..8a4a7df3b74a 100644
> > --- a/Documentation/Makefile
> > +++ b/Documentation/Makefile
> > @@ -75,7 +75,8 @@ quiet_cmd_sphinx = SPHINX  $@ --> file://$(abspath $(BUILDDIR)/$3/$4)
> >        cmd_sphinx = $(MAKE) BUILDDIR=$(abspath $(BUILDDIR)) $(build)=Documentation/userspace-api/media $2 && \
> >       PYTHONDONTWRITEBYTECODE=1 \
> >       BUILDDIR=$(abspath $(BUILDDIR)) SPHINX_CONF=$(abspath $(srctree)/$(src)/$5/$(SPHINX_CONF)) \
> > -     $(PYTHON) $(srctree)/scripts/jobserver-exec \
> > +     PY=$(shell command -v $(PYTHON) 2> /dev/null) \
> > +     $${PY:-"$(PYTHON3)"} $(srctree)/scripts/jobserver-exec \
>
> So I see what you're trying to do, and we definitely want this to work.
> I susped this isn't the right fix, though; it could leave us open to
> similar issues elsewhere in the tree.
>
> Personally, I think that $(PYTHON) should get a working Python if it's
> installed, so I would suggest fixing the top-level Makefile to set it
> correctly.  Masahiro, thoughts on that?
>
> Alternatively, we could just say $(PYTHON3) and explicitly leave Python2
> behind; that needs to happen in the not-too-distant future regardless
> but we haven't decided to actually do it yet.

We are already doing this in linux-next.

I will apply this.
https://lore.kernel.org/patchwork/patch/1373422/




> Thanks,
>
> jon



-- 
Best Regards
Masahiro Yamada