Ruby Debugger install on MacOSx

Dear all,

How can I install and configure Ruby Debugger on MacosX.

My IDE is eclipse

Version: 3.4.2
Build id: M20090211-1700

Debugging Engine not started
The ‘Fast Ruby Debugger (ruby-debug)’ is selected, but the
‘ruby-debug’ gem doesn’t seem to be installed in the selected Ruby

gem install ruby-debug

WARNING: Installing to ~/.gem since /usr/local/lib/ruby/gems/1.8 and
/usr/local/bin aren’t both writable.
WARNING: You don’t have /Users/freeburma/.gem/ruby/1.8/bin in your
gem executables will not run.
Successfully installed ruby-debug-0.10.3
1 gem installed
Installing ri documentation for ruby-debug-0.10.3…
Installing RDoc documentation for ruby-debug-0.10.3…

How can I solve this problem.?

Many Thanks in advance,