Ruby/eclipse in a mixed language project

The shop I’m working for has a bunch of (non-GUI) test automation
written in Python, to which I’ll be adding some GUI scripts written in
Ruby/Watir.

There is an existing svn repository like
https://OurSVNrepository.com/svn/mwtest/trunk/misc

I added a /mwtest/trunk/misc/watir folder to the project and tried to
save my .rb file there, but eclipse is complaining:
Save could not be completed.
Reason: The project trunk is supposed to have a ruby nature.

Googling: “The project trunk is supposed to have a” nature.
gets me 0 results. Do I need to create a separate project for my ruby
scripts? Can I somehow give this project a ‘dual nature’?

I should note that I have RDT 0.9.0 installed, and have a project for
the watir project here that works just fine (I can save to
https://svn.openqa.org/svn/watir/trunk/watir) so my eclipse setup in
general shouldn’t be the issue.

Thanks,
Jeff