我在我的环境中使用Vagrant，我遇到了一个小问题:

$vagrant up

Bringing machine 'default' up with 'virtualbox' provider...
==> default: Box 'base' could not be found. Attempting to find and install...
    default: Box Provider: virtualbox
    default: Box Version: >= 0
==> default: Adding box 'base' (v0) for provider: virtualbox
    default: Downloading: base

An error occurred while downloading the remote file. The error
message, if any, is reproduced below. Please fix this error and try
again.

Couldn't open file /Users/.../base

我已经初始化了我的项目与流浪者初始化，但出于某种原因流浪者拒绝工作。