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

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

[Oleg Nesterov]

After commit 09d8b39563e8 ("get_maintainer: add --json output mode"),
I can no longer use get_maintainer.pl; it fails at compile time if
JSON::PP is not installed even when --json is not requested.

This module is only needed with the --json option. Use "require" to
load this module dynamically inside the "if ($json)" block instead.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
 scripts/get_maintainer.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/get_maintainer.pl b/scripts/get_maintainer.pl
index 16b80a700d4a..8239c8ca0fce 100755
--- 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;
     my $json_encoder = JSON::PP->new->canonical->utf8;
     print($json_encoder->encode(\%result) . "\n");
 } else {
-- 
2.55.0

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

[Joe Perches]

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.

> if JSON::PP is not installed even when --json is not requested.

What version of perl are you using?

I believe JSON is bundled since perl 5.14

> 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.

> 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) {

>      my $json_encoder = JSON::PP->new->canonical->utf8;
>      print($json_encoder->encode(\%result) . "\n");
>  } else {
> 
> ```

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

[Oleg Nesterov]

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

> > 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.

> > 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 ?

Oleg.

[PATCH v2] get_maintainer: lazy load JSON::PP only when --json is used

[Oleg Nesterov]

After commit 09d8b39563e8 ("get_maintainer: add --json output mode"),
I can no longer use get_maintainer.pl; it fails at compile time if
JSON::PP is not installed even when --json is not requested.

This module is only needed with the --json option. Use "require" to
load this module dynamically inside the "if ($json)" block instead.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
 scripts/get_maintainer.pl | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/scripts/get_maintainer.pl b/scripts/get_maintainer.pl
index 16b80a700d4a..b31b4016802f 100755
--- 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 $lk_path = "./";
@@ -663,6 +662,8 @@ my @maintainers = get_maintainers();
 @bug = uniq(@bug) if ($bug);
 
 if ($json) {
+    require JSON::PP;
+
     my @json_maintainers;
     for my $m (@maintainers) {
 	my ($addr, $role);
-- 
2.55.0

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";
}