Mina: 捆绑器没有缓存

我正在使用这个脚本（它是从 mina 0.3 升级的）

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

set :shared_dirs, %w(log public/uploads node_modules)
set :current_path, 'current'
set :term_mode, nil

task :environment do
  invoke :'rbenv:load'
end

task setup: :environment do
  command %[mkdir -p "#{fetch(:shared_path)}/log"]
  command %[chmod g+rx,u+rwx "#{fetch(:shared_path)}/log"]

  command %[mkdir -p "#{fetch(:shared_path)}/public/uploads"]
  command %[chmod g+rx,u+rwx "#{fetch(:shared_path)}/public/uploads"]
  command %[mkdir -p "#{fetch(:shared_path)}/node_modules"]
  command %[chmod g+rx,u+rwx "#{fetch(:shared_path)}/node_modules"]
end

desc 'Deploys the current version to the server.'
task deploy: :environment do
  deploy do
    invoke :'git:clone'
    invoke :'deploy:link_shared_paths'
    invoke :'bundle:install'
    invoke :'rails:db_migrate'
    invoke :'npm_install'
    invoke :'rails:assets_precompile'
    invoke :'deploy:cleanup'

    on :launch do
      command "mkdir -p #{fetch(:current_path)}/tmp/"
      command "touch #{fetch(:current_path)}/tmp/restart.txt"
    end
  end
end

task :restart do
  command "touch #{fetch(:current_path)}/tmp/restart.txt"
end

task :logs do
  command 'echo "Contents of the log file are as follows:"'
  command "tail -f #{fetch(:current_path)}/log/#{fetch(:rails_env)}.log"
end

task :npm_install do
  command 'npm install --production'
end

问题是 - 每次部署完成时， bundle install都会从头开始下载所有 gem。 它在 0.3 版上运行良好。

知道我做错了什么吗？