Xenomai: /dev/rtheap is missing

I tried to install Xenomai 2.5.5.2 on my Ubunto 12.04 PC following the steps in [this guide](http://www.stanley.gatech.edu/skelly/uncategorized/installing-xenomai-on-ubuntu-12-04/#comment-3379) . I haven't changed any configuration options. When I run sudo ./trivial-periodic, I get a message saying Xenomai: /dev/rtheap is missing How can I resolve this error?