$ perl -MJSON -e 1

$ perl -MJSON::XS -e 1
Can't locate JSON/XS.pm in @INC (you may need to install the JSON::XS module) [...]
BEGIN failed--compilation aborted.

$ perl -MCpanel::JSON::XS -e 1

$ perl -MJSON -MData::Dumper -wE 'decode_json(qq{{"foo":"bar"}}); say Dumper %INC;' | grep JSON
$VAR33 = 'JSON/PP.pm';
$VAR34 = '/Users/ntonkin/perl5/perlbrew/perls/perl-5.26.1/lib/5.26.1/JSON/PP.pm';
$VAR37 = 'JSON.pm';
$VAR38 = '/Users/ntonkin/.perlbrew/libs/perl-5.26.1@dev/lib/perl5/JSON.pm';