Calabash-android : rake build error

Calabash-android : rake build error

I am new to calabash-android , i am getting the following error while
executing "rake build " command .
C:\calabash-android\ruby-gem>rake build
rake aborted!
cannot load such file --
C:/Ruby193/lib/ruby/gems/1.9.1/gems/popen4-0.1.2/lib/op en3
lib/calabash-android/helpers.rb:6:in `'
C:/calabash-android/ruby-gem/Rakefile:2:in `load'
C:/calabash-android/ruby-gem/Rakefile:2:in `'
(See full trace by running task with --trace)
These are the steps i have followed
git clone https://github.com/calabash/calabash-android.git
git submodule init
git submodule update
i used gem install popen4 but i again same error Please help me .