Ensure your remote branch is up to date

gistfile1.rb

set :deploy_via, :remote_cache
set :branch, "release"

namespace :git do
  namespace :ensure do
    desc "Check if your local branch is synched with remote branch"
    task :pushed do  
      local = `git rev-parse #{branch}`.chomp
      remote = `git rev-parse remotes/origin/#{branch}`.chomp
      
      unless local == remote
        abort "ABORTING:: You have local commits\n\t#{branch} => #{local}\n\tremotes/origin/#{branch} => #{remote}"
      end
    end
  end
end

before :deploy, "git:ensure:pushed"