When you try to debug a Ruby program you can get this error: LoadError: libruby.so.1.9: cannot open shared object file: No such file or directory.
To fix that you should run these commands in your terminal:
cd /usr/lib/
sudo ln -s libruby-1.9.1.so libruby.so.1.9
# === OR ===
sudo ln -s libruby-1.9.1.so.1.9.1 libruby.so.1.9
#so basically just symlink libruby lib to libruby.so.1.9 (or the new one, depends on your Ruby version, e.g. libruby.so.1.8)
Original article: http://community.activestate.com/node/9794