I just wrote a simple script to check the gems:
https://gist.github.com/dcu/3c06e4ab0e98158c5742c4fd2b31523d
https://gist.github.com/dcu/3c06e4ab0e98158c5742c4fd2b31523d
https://gist.github.com/yb66/44b97baecbeec6900e039ffb9461d31...
Probably depending on version, it seems to be missing a
require 'time'
require 'json'
in my environment.