ruby - cannot load such file -- bundle/bundler/setup (LoadError)

初学 ruby，尝试使用 zhaocai/alfred2-ruby-template 写 Alfred Workflow 时遇到以下错误：

bash$ ruby main.rb 
/Users/tranch/.rvm/rubies/ruby-2.2.0/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require': cannot load such file -- bundle/bundler/setup (LoadError)
    from /Users/tranch/.rvm/rubies/ruby-2.2.0/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    from main.rb:5:in `
'

Google 了下相关关键词，都说因为没装 bundler，但是反复验证了一番，证明确实是都安装了：

bash$ which gem
/Users/tranch/.rvm/rubies/ruby-2.2.0/bin/gemmaster*

$ gem list -d bundler

*** LOCAL GEMS ***

bundler (1.10.3)
    Authors: André Arko, Terence Lee, Carl Lerche, Yehuda Katz
    Homepage: http://bundler.io
    License: MIT
    Installed at: /Users/tranch/.rvm/gems/ruby-2.2.0

    The best way to manage your application’s dependencies

bundler-unload (1.0.2)
    Author: Michal Papis
    Homepage: https://github.com/mpapis/bundler-unload
    License: Apache 2.0
    Installed at: /Users/tranch/.rvm/gems/ruby-2.2.0@global

    Allow unloading bundler after Bundler.load

rubygems-bundler (1.4.4)
    Authors: Josh Hull, Michal Papis
    Homepage: http://mpapis.github.com/rubygems-bundler
    License: Apache-2.0
    Installed at: /Users/tranch/.rvm/gems/ruby-2.2.0@global

    Stop using bundle exec

$ which bundle
/Users/tranch/.rvm/gems/ruby-2.2.0/bin/bundle

$ bundle
Using fuzzy_match 2.1.0
Using builder 3.2.2
Using gyoku 1.3.1
Using moneta 0.8.0
Using nori 2.6.0
Using plist 3.1.0
Using terminal-notifier 1.6.3
Using alfred-workflow 2.0.5
Using bundler 1.10.3
Bundle complete! 2 Gemfile dependencies, 9 gems now installed.
Bundled gems are installed into ./bundle.

求解。