thufir@arrakis:~/sun_tutorial$ 
thufir@arrakis:~/sun_tutorial$ ruby build.rb 
./compile.rb:2: warning: parenthesize argument(s) for future version
./compile.rb:2:in `compile': stack level too deep (SystemStackError)
        from ./compile.rb:2:in `compile'
        from build.rb:4
thufir@arrakis:~/sun_tutorial$ 
thufir@arrakis:~/sun_tutorial$ cat build.rb 
require 'compile'


compile
thufir@arrakis:~/sun_tutorial$ 
thufir@arrakis:~/sun_tutorial$ cat compile.rb 
def compile
        system(echo compile)
end
thufir@arrakis:~/sun_tutorial$