Add job prefix to error messages.

gclient_utils.py

 # Copyright (c) 2012 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.
 
 """Generic utils."""
 
 import codecs
 import logging
 import os
 import Queue
 import re
 import stat
 import subprocess
 import sys
 import tempfile
 import threading
 import time
 import urlparse
 
 import subprocess2
 
 
 class Error(Exception):
   """gclient exception class."""
-  pass
-
+  def __init__(self, msg, *args, **kwargs):
+    index = getattr(threading.currentThread(), 'index', 0)
+    if index:
+      msg = '\n'.join('%d> %s' % (index, l) for l in msg.splitlines())
+    super(Error, self).__init__(msg, *args, **kwargs)
 
 def SplitUrlRevision(url):
   """Splits url and returns a two-tuple: url, rev"""
   if url.startswith('ssh:'):
     # Make sure ssh://user-name@example.com/~/test.git@stable works
     regex = r'(ssh://(?:[-\w]+@)?[-\w:\.]+/[-~\w\./]+)(?:@(.+))?'
     components = re.search(regex, url).groups()
   else:
     components = url.split('@', 1)
     if len(components) == 1:
@@ skipping 831 matching lines @@
 
   Python on OSX 10.6 raises a NotImplementedError exception.
   """
   try:
     import multiprocessing
     return multiprocessing.cpu_count()
   except:  # pylint: disable=W0702
     # Mac OS 10.6 only
     # pylint: disable=E1101
     return int(os.sysconf('SC_NPROCESSORS_ONLN'))