edx---安装 vagrant - vbguest 插件

An error occurred during installation of VirtualBox Guest Additions 4.3.20. Some functionality may not work as intended.
In most cases it is OK that the "Window System drivers" installation failed.
stdin: is not a tty
==> default: Checking for guest additions in VM...
==> default: Configuring and enabling network interfaces...
333tianhao@tianhao-Vostro-3900:~/workspace/QST_MOOC/trunk$ vagrant plugin install vagrant-vbguest
Installing the 'vagrant-vbguest' plugin. This can take a few minutes...
Bundler, the underlying system Vagrant uses to install plugins,
reported an error. The error is shown below. These errors are usually
caused by misconfigured plugin installations or transient network
issues. The error from Bundler is:

An error occurred while installing ffi (1.9.10), and Bundler cannot continue.
Make sure that `gem install ffi -v '1.9.10'` succeeds before bundling.

Gem::RemoteFetcher::FetchError: Errno::ECONNRESET: Connection reset by peer - SSL_connect (https://rubygems.org/gems/ffi-1.9.10.gem)
333tianhao@tianhao-Vostro-3900:~/workspace/QST_MOOC/trunk$ vagrant halt
==> default: Attempting graceful shutdown of VM...
333tianhao@tianhao-Vostro-3900:~/workspace/QST_MOOC/trunk$ vagrant up