deploy.rb

namespace :symfony do
  namespace :assets do
    desc "Updates assets version"
    task :update_version do
        run "sed -i 's/\\(assets_version: \\)\\(.*\\)$/\\1 #{real_revision}/g' #{latest_release}/app/config/config.yml"
    end
  end
end

before "symfony:assetic:dump" do
  symfony.assets.update_version
end