title: Attempting to access file system from jenkinsfile
body: <p>I'm trying to access the file system from a Jenkinsfile using groovy. I'm following the suggestion in this SO thread: 
  <a href="https://stackoverflow.com/questions/3662144">Recursive listing of all files matching a certain filetype in Groovy</a></p>
  
  <p>I've already given access to </p>
  
  <pre><code>new java.io.File java.lang.String
  staticField groovy.io.FileType FILES
  </code></pre>
  
  <p>under Script Approvals.</p>
  
  <p>However this line is failing without an error message:</p>
  
  <pre><code>new File('.').eachFileRecurse(FILES) {
  </code></pre>
  
  <p>Here's the broader code block in question:</p>
  
  <pre><code>stage("Install") {
    print "here a"
    new File('.').eachFileRecurse(FILES) {
      print "here c"
      if(it.name.endsWith(".sh")) {
        print "here d"
        println it
      }
    }
    print "here b"
  </code></pre>
  
  <p>Here's the console output from that section:</p>
  
  <pre><code>[Pipeline] stage
  [Pipeline] { (Install)
  [Pipeline] echo
  here a
  [Pipeline] }
  [Pipeline] // stage
  [Pipeline] echo
  Email Recipients: opike99@gmail.com, opike@yahoo.com
  [Pipeline] emailext
  messageContentType = text/html; charset=UTF-8
  Adding recipients from project recipient list
  Adding recipients from trigger recipient list
  Setting In-Reply-To since last build was not successful
  </code></pre>