Cannot use ruby-debug19 with 1.9.3-p0?

Possible Duplicate:
Rails 3.1 and Ruby 1.9.3p125: ruby-debug19 still crashes with “Symbol not found: _ruby_threadptr_data_type”

I run this:

gem install ruby-debug19

And in my cucumber env.rb file, I have this:

require 'ruby-debug'

When I try to run, though, I get this exception:

/home/skendall/.rvm/gems/ruby-1.9.3-p0/gems/ruby-debug-base19-0.11.25/lib/ruby_debug.so: undefined symbol: ruby_current_thread - /home/skendall/.rvm/gems/ruby-1.9.3-p0/gems/ruby-debug-base19-0.11.25/lib/ruby_debug.so (LoadError)

What do I need to do to get ruby-debug to work with 1.9.3-p0?

Solution

UPDATE: ruby-debug19 is not maintained anymore. This question and my answer have become irrelevant, it's far easier to use the 'debugger' gem instead.

See Debugging in ruby 1.9

I also ran into this, and found the solution in Ruby 1.9.3 and ruby-debug. You need to install not-yet-officially-released versions of ruby-debug-base19 and linecache19. The currently released versions indeed cause the exception you had.

Use this gist.

#To install ruby-debug on Ubuntu ruby-1.9.3 you need to download from http://rubyforge.org/frs/?group_id=8883

linecache19-0.5.13.gem 
ruby_core_source-0.1.5.gem 
ruby-debug19-0.11.6.gem 
ruby-debug-base19-0.11.26.gem

#Then in your console

export RVM_SRC=/your/path/to/ruby-1.9.3
# Note, your source path should be something like /home/user/.rvm/src/ruby-1.9.3-p0

gem install archive-tar-minitar
gem install ruby_core_source-0.1.5.gem -- --with-ruby-include=/$RVM_SRC
gem install linecache19-0.5.13.gem -- --with-ruby-include=/$RVM_SRC
gem install ruby-debug-base19-0.11.26.gem -- --with-ruby-include=/$RVM_SRC
gem install ruby-debug19-0.11.6.gem -- --with-ruby-include=/$RVM_SRC