Changelog for unix-runescape-client-4.3.5-16.1.noarch.rpm :
Thu Jun 1 14:00:00 2017 Brenton Horne - 4.3.5-4
- Turns out the request was right https://pkgs.org/download/perl(JSON::backportPP) shows that fewer distros have perl(JSON::backportPP) there are distros with Perl-JSON (https://pkgs.org/download/perl-JSON)