Don't know how to build task 'start' when run 'cap production deploy' for capistrano 3.8.0 with Rails

Add install_plugin Capistrano::Puma into your Capfile after require 'capistrano/puma'.

capistrano3-puma moved to 3.0 a few days ago. This line is required for loading default puma tasks in this version.

See https://github.com/seuros/capistrano-puma#usage