I'm currently gettng the following error attempt to install the debugger using: sudo gem install ruby-debug
Building native extensions. This could take a while...
ERROR: Error installing ruby-debug:
ERROR: Failed to build gem native extension.
can't find header files for ruby.
Gem files will remain installed in /Library/Ruby/Gems/1.8/gems/linecache-0.43 for inspection.
Results logged to /Library/Ruby/Gems/1.8/gems/linecache-0.43/ext/gem_make.out