pry-remote

if you want to do pry-remote this worked for me under a nginx + passenger environment

add pry and pry-remote to your gemfile

add binding.pry-remote to where you want to debug

class MyClass
    def do_this
        a = 123
        binding.pry-remote
    end
end

Navigate in your browser to where your code gets executed, then try this in the terminal

pry-remote -r ./config/environment.rb

and voila!