nix-generate-from-cpan: use Module::CoreList to detect core modules

The previous way of detecting core modules failed to filter "if" and
possibly other core modules.

1 files changed, 3 insertions, 8 deletions

diff --git a/maintainers/scripts/nix-generate-from-cpan.pl b/maintainers/scripts/nix-generate-from-cpan.pl
index d258f4df8d8e..f02af4ea6693 100755
--- a/maintainers/scripts/nix-generate-from-cpan.pl
+++ b/maintainers/scripts/nix-generate-from-cpan.pl
@@ -6,6 +6,7 @@ use warnings;
 
 use CPAN::Meta();
 use CPANPLUS::Backend();
+use Module::CoreList;
 use Getopt::Long::Descriptive qw( describe_options );
 use JSON::PP qw( encode_json );
 use Log::Log4perl qw(:easy);
@@ -278,14 +279,8 @@ sub get_deps {
     foreach my $n ( $deps->required_modules ) {
         next if $n eq "perl";
 
-        # Figure out whether the module is a core module by attempting
-        # to `use` the module in a pure Perl interpreter and checking
-        # whether it succeeded. Note, $^X is a magic variable holding
-        # the path to the running Perl interpreter.
-        if ( system("env -i $^X -M$n -e1 >/dev/null 2>&1") == 0 ) {
-            DEBUG("skipping Perl-builtin module $n");
-            next;
-        }
+        my @core = Module::CoreList->find_modules(qr/^$n$/);
+        next if (@core);
 
         my $pkg = module_to_pkg( $cb, $n );