As a followup from my psa: you can now debug with pry on jruby I have finally uploaded my fork of pry-debugger — the pry-debugger-jruby gem — onto rubygems!

The original post has been updated, but as a reminder, using it is as simple as adding

gem 'pry-debugger-jruby'

to your gemfile, and then starting pry on JRuby.

Feedback and issues are very welcome! :)