Ruby and Qt integration on Ubuntu 10.04

Hi I wanted to run make an GUI with Qt in Ruby. I downloaded qt4-qtruby-2.1.0 from http://rubyforg开发者_C百科e.org/frs/?group_id=181&release_id=12479 But when I run cmake in it's directory I get this error:

CMake Error at cmake/modules/FindRUBY.cmake:85 (MESSAGE):
  Could not find Ruby
Call Stack (most recent call first):
  CMakeLists.txt:77 (FIND_PACKAGE)

-- Configuring incomplete, errors occurred!

What I'm doing wrong?

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Perhaps you're missing ruby-dev, the development part of the ruby package?