Debugging Ruby code in Eclipse should be easy. After all, there is Aptana Studio which integrates the Ruby debugger, and RVM to manage the Ruby installations. Or so I thought. The problem is that I cannot work without a debugger. Using print statements to trace program flow makes me loose hair, and trial-and-error F5ing in the web browser can hardly be called systematic solving of a programming problem. So I had to make it work. After several hours of setup and configuration, running into the next problem, searching the web again, retrying, and consuming caffeine overdoses in the process, debugging eventually worked. To save those trying after me from running into the same trouble, the steps that finally succeeded are documented below. The following instructions have been verified on Ubuntu 12.04 32bit.