当我尝试做 Vagrant up 时，我收到此错误消息：
Failed to load the "berkshelf" plugin. View logs for more details.
Vagrant failed to initialize at a very early stage:
Failed to load the "vagrant-berkshelf" plugin. The output from loading
the plugin is shown below. View the logs for complete details.
stdout:
stderr: /Users/user/.vagrant.d/gems/gems/berkshelf-2.0.18/lib/berkshelf.rb:25: warning: already initialized constant DEFAULT_FILENAME
/Users/user/.vagrant.d/gems/gems/berkshelf-2.0.18/lib/berkshelf/cookbook_generator.rb:5: warning: already initialized constant LICENSES
Berksfile 正常安装，直到今天一切正常，有人知道如何解决这个问题吗？