title: vfsstream: file_get_contents() failed to open stream: stream_open call failed
body: <p>I have set up a vfsstream block device and I'm trying to call <code>file_get_contents()</code> on it. 
  However the call to <code>vfsStreamWrapper::stream_open</code> fails and therefore the stream cannot be opened.</p>
  
  <p>Here is my code:</p>
  
  <pre><code>$this-&gt;root = vfsStream::setup('root');
  $this-&gt;root-&gt;addChild(new vfsStreamBlock('test_block_device'));
  $this-&gt;root-&gt;addChild(new vfsStreamFile('not_block_device'));
  echo file_get_contents('vfs://root/test_block_device/size');
  </code></pre>
  
  <p>Here is the error:</p>
  
  <blockquote>
    <p>file_get_contents(vfs://root/test_block_device/size): failed to open stream: "org\bovigo\vfs\vfsStreamWrapper::stream_open" call failed</p>
  </blockquote>
  
  <p><a href="https://github.com/mikey179/vfsStream/issues/70" rel="nofollow">Here is the closest issue I've found on this</a></p>
  
  <p>However his was an issue with phpunit's teardown and mine happens mid-test.</p>