Issues in deploying Rails on EC2 using Rubber. script/rubber file missing

I am trying to deploy a rails3.1 app to EC2 using rubber 1.15.0 gem. I
followed the instructions in the quick start guide here: i also setup
private and public keys correctly as mentioned in faq. However, Almost
towards the end of >cap rubber:generate_staging command I get this

    [] /bin/bash -l -c 'sudo -p '\''sudo password:
'\'' bash -l -c '\''cd /mnt/app-production/releases/20120314070940 &&
RUBBER_ENV=production RAILS_ENV=production ./script/rubber config
     ** [out ::] bash: ./script/rubber: No such
file or directory
        command finished in 418ms
    failed: "/bin/bash -l -c 'sudo -p '\\''sudo password: '\\'' bash -
l -c '\\''cd /mnt/app-production/releases/20120314070940 &&
RUBBER_ENV=production RAILS_ENV=production ./script/rubber config '\
\'''" on

I looked at script folder and found no rubber file. It seems that that
ruber script file is NOT generated after vulcanize command. Does
anyone know what command do I need to generate that rubber script

I couldn't find any help regarding this anywhere online.

Please use the issue tracker of this project