A set of patches to Ruby MRI 1.9.3 and 1.9.2 that adds run-time introspection, a call frame object, and other run-time support for things like debuggers. Necessary patches and some simple patch code are found in the git repository. See https://github.com/rocky/rb-threadframe/wiki/How-to-Install for how to install.
Gemfile gem 'rb-threadframe', '~> 0.41'
install gem install rb-threadframe