$ perl -v | head -2 | tail -1 This is perl 5, version 24, subversion 0 (v5.24.0) built for darwin-thread-multi-2level $ perl -e 'use 5.020; no 5.024' Perls since v5.24.0 too modern--this is v5.24.0, stopped at -e line 1. BEGIN failed--compilation aborted at -e line 1. $