The smart proxy (1.22/23) on Ubuntu 18LTS will not start due to some missing reference to dynflow (require 'dynflow') or some such. I can make it get past this by requiring it in smart_proxy_main.rb but it gives an error complaining about the future method being missing ([E] undefined method `future' for Concurrent:Module (NoMethodError). I think this is related to how ruby has deprecated the concurrent future method in favor of promises, and perhaps not this is now reflected in the Ubuntu packaging.