whenever_with_cap_multistage.rb

require 'whenever/capistrano'

##
# Force Whenever to use the Capistrano stage. We use a lambda to delay execution
# until absolutely necessary.
set :whenever_command, lambda { "whenever --set environment=#{fetch(:stage, 'production')}" }

We added it to our bundler, and the following task can be found in our common.rb

desc "Set up cron jobs for this release"
task :setup_crontab do
run "cd #{current_release} && whenever --update-crontab comments"
end

Whenever actually comes with a very similar, and configurable, Capistrano task. What I'm doing in my gist is modifying their setting for the "whenever" executable so that it dynamically sets the environment to use based on the current Capistrano environment used (e.g. staging, dev, production).