Go to RubyForge and download:
Then:
# linecache
% gem install linecache19-0.5.13.gem -- --with-ruby-include=$rvm_path/src/ruby-1.9.3-p0
# ruby-debug-base19
% gem install ruby-debug-base19-0.11.26.gem -- --with-ruby-include=$rvm_path/src/ruby-1.9.3-p0