Last week I decided to fix some failing specs for Rubinius 1.9 mode. If you haven't done that before continue reading you will be surprised how easy that can be.
To get started you need a working clone of Rubinius. You can find instructions in the docs.
Now let's see what specs are failing. I consult the failing tags which can be found in:
There are many specs still failing so I go through some and find something interesting in: