Fixing a small bug and changing the os to match the new environment.

testing/legion/client_lib.py

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Defines the client library."""
 
 import argparse
 import datetime
 import logging
 import os
@@ skipping 184 matching lines @@
         ])
 
     self._ExecuteProcess(cmd)
 
   def _ExecuteProcess(self, cmd):
     """Executes a process, waits for it to complete, and checks for success."""
     logging.debug('Running %s', ' '.join(cmd))
     p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
     _, stderr = p.communicate()
     if p.returncode != 0:
-      stderr.seek(0)
       raise Error(stderr)
 
   def OnConnect(self, ip_address):
     """Receives client ip address on connection."""
     self._ip_address = ip_address
     self._connected = True
     self._rpc = common_lib.ConnectToServer(self._ip_address)
     logging.info('%s connected from %s', self._name, ip_address)
     self._connect_event.set()