linux-kernel - Re: [PATCH 2/2] perf build: Add Debian/Ubuntu python-is-python3

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CAMuHMdUUH2AN7tE3C7cPWeNJDW6jL9vQOktaRDW2HChDwvroSg@mail.gmail.com>
Date: Fri, 17 Oct 2025 18:39:04 +0200
From: Geert Uytterhoeven <geert@...ux-m68k.org>
To: Leo Yan <leo.yan@....com>
Cc: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>, 
	Arnaldo Carvalho de Melo <acme@...nel.org>, Namhyung Kim <namhyung@...nel.org>, 
	Mark Rutland <mark.rutland@....com>, 
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>, Jiri Olsa <jolsa@...nel.org>, 
	Ian Rogers <irogers@...gle.com>, Adrian Hunter <adrian.hunter@...el.com>, 
	linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] perf build: Add Debian/Ubuntu python-is-python3

Hi Leo,

On Fri, 17 Oct 2025 at 14:29, Leo Yan <leo.yan@....com> wrote:
> On Thu, Oct 16, 2025 at 02:44:12PM +0200, Geert Uytterhoeven wrote:
> > The build looks for "python" and "python-config", while modern
> > distributions provide only "python3" and "python3-config" by default.
> > Suggest installing "python-is-python3" and "python-dev-is-python3", as
> > available on Debian 11 (bullseye) and Ubuntu 20.04 LTS (focal) and
> > later.
>
> Seems to me, this change is not necessary. The Makefile [1] searches
> python[2|3]/python[2|3]-cofig if un-versioned executables are not found.
>
> I confirmed that I can build successfully without installation
> python-dev-is-python3 package.

    $ sudo apt remove python-dev-is-python3 python-is-python3
    $ make tools/perf

Indeed, it still works. I am quite sure I had to install both, and
even verified that uninstalling them again broke the build again before
creating my patch.

/me dives deeper.

Aha, I found it.  After uninstalling python3-dev, I got into the same
state as yesterday:

    $ make tools/perf
    [...]
    Makefile.config:875: No python interpreter was found: disables
Python support - please install python-devel/python-dev
    Makefile.config:918: *** ERROR: No python interpreter needed for
jevents generation. Install python or build with NO_JEVENTS=1..  Stop.

So these error messages sound like python is missing. And "python"
is indeed missing, but "python3" is available.
Hence I installed python-is-python3, but that turned out not to be
sufficient.
Hence I also installed python-dev-is-python3, and that fixed the issue,
as python-dev-is-python3 depends on python3-dev, so the latter was
installed, too.

After removing python-is-python3 and python-dev-is-python3, everything
keeps on working.  But if you never installed python3-dev manually,
and run "sudo apt autoremove", python3-dev is uninstalled, reintroducing
the issue.

So just recomming to install python-dev-is-python3 in the error
message should be sufficient?

What do you think?
Thanks!

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@...ux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds