rake aborted on ubuntu

[srinath]

Hi, I was got this error when trying to install adva_cms . Using ruby - 1.8.6 , rails - 2.3.4 (also had 2.3.5) and all gems on Ubuntu .

Checking out files: 100% (2977/2977), done. executing git checkout -b tag/0.3.0 0.3.0 from /home/srinath/adva_cms/vendor/adva Switched to a new branch "tag/0.3.0" rake adva:install:core -R vendor/adva/engines/adva_cms/lib/tasks rake aborted! undefined method `unix?' for #Rake::Application:0xb7d72e38

(See full trace by running task with --trace) rake adva:assets:install rake aborted! Don't know how to build task 'adva:assets:install'

(See full trace by running task with --trace) applied http://github.com/svenfuchs/adva_cms/raw/master/templates/adva-cms.0.3.0.rb srinath@srinath-laptop:~$

Could you please tell how to solve this issue and run , i'm interested to run this cms for my project . thanks.