Re: [PATCH] get_maintainer: lazy load JSON::PP only when --json is used

[Joe Perches]

On Fri, 2026-10-30 at 17:17 +0100, Oleg Nesterov wrote:
> On 10/30, Joe Perches wrote:
> > On Fri, 2026-10-30 at 16:43 +0100, Oleg Nesterov wrote:
> After commit 09d8b39563e8 ("get_maintainer: add --json output mode"),
> > > I can no longer use get_maintainer.pl; it fails at compile time
> > 
> > Just verifying that you mean when using perl directly and
> > not something like perlcc.
> 
> Yes,
> 
> > > if JSON::PP is not installed even when --json is not requested.
> > What version of perl are you using?
> v5.42.3
> > I believe JSON is bundled since perl 5.14
> Well, JSON::PP is not installed on my Fedora release 44

Hmm.  Odd.

> > > This module is only needed with the --json option. Use "require" to
> > > load this module dynamically inside the "if ($json)" block instead.
> > The patch may be sensible but could fail the same way
> > if you used the --json option with your version.
> 
> Of course, "./scripts/get_maintainer.pl --json ..." will still fail
> the same way without JSON::PP. But with this patch get_maintainer.pl
> works without the --json option.

What does that failure output?

> > > diff --git a/scripts/get_maintainer.pl b/scripts/get_maintainer.pl
> > []
> > > @@ -21,7 +21,6 @@ use Cwd;
> > >  use File::Find;
> > >  use File::Spec::Functions;
> > >  use open qw(:std :encoding(UTF-8));
> > > -use JSON::PP;
> > >  
> > >  my $cur_path = fastgetcwd() . '/';
> > >  my $lk_path = "./";
> > > @@ -685,6 +684,7 @@ if ($json) {
> > >      $result{web} = \@web if ($web);
> > >      $result{bug} = \@bug if ($bug);
> > >  
> > > +    require JSON::PP;
> > style nit:
> > I likely would have placed this require immediately after the
> > if ($json) {
> 
> I am fine either way... should I send V2 ?

Dunno.  Depending on the current failure output
maybe adding something like the below is better:

use Module::Load::Conditional qw(check_install);

if (!check_install(module => 'JSON:PP')) {
    die "$P: --json not available - missing perl module JSON:PP\n";
}