[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.

[Salvatore Bonaccorso]

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  /([^,)]+)/.

# 5.10.y specific regression
#regzbot introduced: 443b16ee3d9ce0a3ece0e3526a5af883e5b16eaf
#regzbot link: https://bugs.debian.org/1064035

Regards,
Salvatore