deploy.rb

require 'mina/bundler'
require 'mina/rails'
require 'mina/git'

# Basic settings:
# domain     - The hostname to SSH to
# deploy_to  - Path to deploy into
# repository - Git repo to clone from (needed by mina/git)
# user       - Username in the  server to SSH to (optional)


set :domain,        # actual info removed
set :deploy_to, 
set :repository, 
 set :user, 'deploy'
# set :port, '30000'

  task :env do                                                                                                                                                                                                
    queue %{
      echo "-----> Loading environment"
      #{echo_cmd %[source "/usr/local/rvm/environments/ruby-1.9.3-p135@gemset"]}  ------> this line as suggested by you didn't work hence tried the below line but still failed with the same problem
            #{echo_cmd %[source "/usr/local/rvm/gems/ruby-1.9.3-p125@global"]} 
    }
  end

desc "Deploys the current version to the server."
task :deploy do
  invoke :env
  deploy do
    # Put things that will set up an empty directory into a fully set-up
    # instance of your project.
    invoke :'git:clone'
    invoke :'bundle:install'
    invoke :'rails:db_migrate'
    invoke :'rails:assets_precompile'

    to :launch do
      queue 'touch tmp/restart.txt'
    end
  end
end