This fix is for anyone that has NetBeans 6.9.1, Ruby 1.9.2, Rails 3.0.0, already installed, and decides to add support for debugging on Windows XP.

That was my configuration, but it didn’t work properly. A debug session always ended with an error about a non existing script/rails file. After some research, today I discovered this fix that eventually allows me to cleanly debug a Ruby on Rails 3.0.0 project.

  1. Download DevKit 4.5.0 from
  2. Install DevKit as described at
  3. Enter the command
  4. Enter the command
  5. Edit the file (Ruby folder)/lib/ruby/gems/1.9.1/gems/ruby-debug-ide19-0.4.12/lib/ruby-debug-ide.rb as follows This one isn’t required, but I find wrong labels very distracting
  6. Edit the file (Ruby folder)/lib/ruby/gems/1.9.1/gems/ruby-debug-ide19-0.4.12/bin/rdebug-ide.rb as follows See also:
  1. Edit the file (Project folder)/Gemfile as follows
  2. delete the file (Project folder)/Gemfile.lock
  3. Enter the command

That’s all. I hope it’ll work for you too :-)