Re: [regression 5.10.y] linux-doc builds: Global symbol "$args" requires explicit package name (did you forget to declare "my $args"?) at ./scripts/kernel-doc line 1236.

From: Salvatore Bonaccorso <carnil@debian.org>
To: Jonathan Corbet <corbet@lwn.net>
Cc: regressions@lists.linux.dev, stable@vger.kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Ben Hutchings <ben@decadent.org.uk>,
	Kees Cook <keescook@chromium.org>,
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	Aditya Srivastava <yashsri421@gmail.com>,
	1064035@bugs.debian.org
Subject: Re: [regression 5.10.y] linux-doc builds: Global symbol "$args" requires explicit package name (did you forget to declare "my $args"?) at ./scripts/kernel-doc line 1236.
Date: Mon, 4 Mar 2024 21:00:36 +0100	[thread overview]
Message-ID: <ZeYoZNJaZ4ejONTZ@eldamar.lan> (raw)
In-Reply-To: <877ciiw1yp.fsf@meer.lwn.net>

Hi Jonathan,

On Mon, Mar 04, 2024 at 06:39:26AM -0700, Jonathan Corbet wrote:
> Salvatore Bonaccorso <carnil@debian.org> writes:
> 
> > Hi,
> >
> > Ben Hutchings reported in https://bugs.debian.org/1064035 a problem
> > with the kernel-doc builds once 3080ea5553cc ("stddef: Introduce
> > DECLARE_FLEX_ARRAY() helper") got applied in 5.10.210 (as
> > prerequisite of another fix in 5.10.y):
> >
> >> The backport of commit 3080ea5553cc "stddef: Introduce
> >> DECLARE_FLEX_ARRAY() helper" modified scripts/kernel-doc and
> >> introduced a syntax error:
> >> 
> >> Global symbol "$args" requires explicit package name (did you forget to declare "my $args"?) at ./scripts/kernel-doc line 1236.
> >> Global symbol "$args" requires explicit package name (did you forget to declare "my $args"?) at ./scripts/kernel-doc line 1236.
> >> Execution of ./scripts/kernel-doc aborted due to compilation errors.
> >> 
> >> This doesn't stop the documentation build process, but causes the
> >> documentation that should be extracted by kernel-doc to be missing
> >> from linux-doc-5.10.
> >> 
> >> We should be able to fix this by eithering backport commit
> >> e86bdb24375a "scripts: kernel-doc: reduce repeated regex expressions
> >> into variables" or replacing /$args/ with /([^,)]+)/.
> >> 
> >> Ben.
> >
> > What would be prefered here from stable maintainers point of view?
> > AFAICS e86bdb24375a ("scripts: kernel-doc: reduce repeated regex
> > expressions into variables") won't apply cleanly and needs some
> > refactoring. The alternative pointed out by Ben would be to replace
> > the /$args/ with  /([^,)]+)/.
> 
> Hmm...this is the first I see of any of this...
> 
> The latter fix seems like the more straightforward of the two.  The only
> concern might be if there are other kernel-doc backports that might run
> afoul of the same problem, hopefully not.

Ok. In the sprit of the stable series rules we might try the later and
if it's not feasible pick the first variant?

> But this makes me wonder if there are other stable kernels that are
> affected as well.  I guess that, despite all of the testing being done
> on stable updates, nobody is testing the docs build?

Only 5.10.y is affected AFAICT, and the reaso nis that the cherry-pick
of ("stddef: Introduce DECLARE_FLEX_ARRAY() helper") in 5.10.y (as
requisite of the smb fixes) requires as well e86bdb24375a ("scripts:
kernel-doc: reduce repeated regex expressions into variables").

3080ea5553cc ("stddef: Introduce DECLARE_FLEX_ARRAY() helper") is in 
5.10.210, 5.15.54 and 5.16-rc1.

e86bdb24375a ("scripts: kernel-doc: reduce repeated regex expressions
into variables") is in 5.14-rc1.

So it's covered for the later series, but causes problems in the
5.10.y.

Regards,
Salvatore