title: pexpect.EOF: End Of File (EOF). Exception style platform
body: <p>With pexpect I am spawning child process and doing 'ssh' remote box. It was working fine from last many days, suddenly now i whenever i am trying to spawn child process it's throwing below Error. not sure what is going on. </p>
  
  <p>Till now i was using pexpect 3.1, i encounter this problem. so I  upgrade it to 3.2, but still facing same issue. </p>
  
  <pre><code>&gt;&gt;&gt; child = pexpect.spawn('ssh -o StrictHostKeyChecking=no centos@192.168.2.23')
  &gt;&gt;&gt; child.expect([pexpect.TIMEOUT,'[P|p]assword: '])
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
    File "/usr/lib/python2.7/dist-packages/pexpect/__init__.py", line 1418, in expect
      timeout, searchwindowsize)
    File "/usr/lib/python2.7/dist-packages/pexpect/__init__.py", line 1433, in expect_list
      timeout, searchwindowsize)
    File "/usr/lib/python2.7/dist-packages/pexpect/__init__.py", line 1521, in expect_loop
      raise EOF(str(err) + '\n' + str(self))
  pexpect.EOF: End Of File (EOF). Exception style platform.
  &lt;pexpect.spawn object at 0x7fe923a8b710&gt;
  version: 3.2
  command: /usr/bin/ssh
  args: ['/usr/bin/ssh', '-o', 'StrictHostKeyChecking=no', 'centos@192.168.2.23']
  searcher: &lt;pexpect.searcher_re object at 0x7fe923a8b750&gt;
  buffer (last 100 chars): ''
  before (last 100 chars): 'AL PROSECUTION.\r\nPermission denied (publickey,gssapi-keyex,gssapi-with-mic,keyboard-interactive).\r\r\n'
  after: &lt;class 'pexpect.EOF'&gt;
  match: None
  match_index: None
  exitstatus: 255
  flag_eof: True
  pid: 2202
  child_fd: 3
  closed: False
  timeout: 30
  delimiter: &lt;class 'pexpect.EOF'&gt;
  logfile: None
  logfile_read: None
  logfile_send: None
  maxread: 2000
  ignorecase: False
  searchwindowsize: None
  delaybeforesend: 0.05
  delayafterclose: 0.1
  delayafterterminate: 0.1
  </code></pre>