Hmm, the "use Modern::Perl '2017';" line is failing with this error:

Feature bundle "5.24" is not supported by Perl 5.22.1 at /home/steemitdev/perl5/lib/perl5/Modern/Perl.pm line 38.
BEGIN failed--compilation aborted at bin/steemit_client.pl line 2.

I'm using an Ubuntu 16.04.3 (LTS) VM. Just did "sudo apt update" and "sudo apt upgrade" but the newest version of Perl available is 5.22. Don't want to upgrade to a newer Ubuntu version that's not LTS (long-term support).

Aha! I see that your link to the Perlbrew tutorial should resolve my issue. Great, thanks!