Can't run RubyMine debugger with RVM, Ruby 1.9.2 and Rails 3

I've setup a fresh Ubuntu install and followed this guide to install RVM, Ruby 1.9.2 and Rails 3.

Then I installed RubyMine 3.0, it automatically detected the Ruby 1.9.2 SDK from the RVM path, so that's ok. I can start the server perfectly (green play button).

Now the problem is I can't debug it because it throws the following exception after startup.

/home/eparizzi/.rvm/rubies/ruby-1.9.2-p180/bin/ruby -e at_exit{sleep(1)};$stdout.sync=true;$stderr.sync=true;load($0=ARGV.shift) /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/ruby-debug-ide-0.4.16/bin/rdebug-ide --port 39879 -- /home/eparizzi/Projects/Delko/src/script/rails server -p 3000 -b 0.0.0.0 -e development
Fast Debugger (ruby-debug-ide 0.4.16, ruby-debug-base 0.11) listens on 127.0.0.1:39879
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/ruby-debug19-0.11.6/cli/ruby-debug/interface.rb:128:in `<module:Debugger>'
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/ruby-debug19-0.11.6/cli/ruby-debug/interface.rb:1:in `<top (required)>'
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/ruby-debug19-0.11.6/cli/ruby-debug/processor.rb:1:in `require_relative'
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/ruby-debug19-0.11.6/cli/ruby-debug/processor.rb:1:in `<top (required)>'
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/ruby-debug19-0.11.6/cli/ruby-debug.rb:6:in `require_relative'
    /ho开发者_运维技巧me/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/ruby-debug19-0.11.6/cli/ruby-debug.rb:6:in `<top (required)>'
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/bundler-1.0.10/lib/bundler/runtime.rb:68:in `require'
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/bundler-1.0.10/lib/bundler/runtime.rb:68:in `block (2 levels) in require'
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/bundler-1.0.10/lib/bundler/runtime.rb:66:in `each'
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/bundler-1.0.10/lib/bundler/runtime.rb:66:in `block in require'
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/bundler-1.0.10/lib/bundler/runtime.rb:55:in `each'
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/bundler-1.0.10/lib/bundler/runtime.rb:55:in `require'
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/bundler-1.0.10/lib/bundler.rb:120:in `require'
    /home/eparizzi/Projects/Delko/src/config/application.rb:7:in `<top (required)>'
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.5/lib/rails/commands.rb:28:in `require'
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.5/lib/rails/commands.rb:28:in `block in <top (required)>'
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.5/lib/rails/commands.rb:27:in `tap'
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.5/lib/rails/commands.rb:27:in `<top (required)>'
    /home/eparizzi/Projects/Delko/src/script/rails:6:in `require'
    /home/eparizzi/Projects/Delko/src/script/rails:6:in `<top (required)>'
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/ruby-debug-ide-0.4.16/lib/ruby-debug-ide.rb:112:in `debug_load'
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/ruby-debug-ide-0.4.16/lib/ruby-debug-ide.rb:112:in `debug_program'
    /home/eparizzi/.rvm/gems/ruby-1.9.2-p180/gems/ruby-debug-ide-0.4.16/bin/rdebug-ide:87:in `<top (required)>'
    -e:1:in `load'
    -e:1:in `<main>'
Uncaught exception: superclass mismatch for class RemoteInterface

Process finished with exit code 0

I have the following line in the .Gemfile

gem 'ruby-debug19', :require => 'ruby-debug'

Also (following some blog) I installed the ruby-debug-ide gem as follows:

gem install ruby-debug-ide19 -- --with-ruby-include=$rvm_path/src/ruby-1.9.2-p180/ 

it's definitely a gem related debug issue. You shouldn't need to include the debug gem in your .gemfile though. Rubymine should pick it up automatically, so I'd remove it from there to start with.

Make sure you've installed the debug-base gem as well for 1.9

gem install ruby-debug-base19

I remember there was a couple of issues related to debugging in general for 1.9 at the start but I think they've been ironed out now.

Have you seen this article yet? It also might be able to help point you in a direction.

Debugging in ruby 1.9

All the best.

Remove the :require => 'ruby-debug' from your Gemfile and it should work.