Add more error regexps for git retry

git_common.py

 # Copyright 2014 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.
 
 # Monkeypatch IMapIterator so that Ctrl-C can kill everything properly.
 # Derived from https://gist.github.com/aljungberg/626518
 import multiprocessing.pool
 from multiprocessing.pool import IMapIterator
 def wrapper(func):
   def wrap(self, timeout=None):
@@ skipping 74 matching lines @@
 
     # crbug.com/187444
     r'RPC failed; result=\d+, HTTP code = \d+',
 
     # crbug.com/388876
     r'Connection timed out',
 
     # crbug.com/430343
     # TODO(dnj): Resync with Chromite.
     r'The requested URL returned error: 5\d+',
+
+    r'Connection reset by peer',
+
+    r'Unable to look up',
+
+    r'Couldn\'t resolve host',
 )
 
 GIT_TRANSIENT_ERRORS_RE = re.compile('|'.join(GIT_TRANSIENT_ERRORS),
                                      re.IGNORECASE)
 
 # git's for-each-ref command first supported the upstream:track token in its
 # format string in version 1.9.0, but some usages were broken until 2.3.0.
 # See git commit b6160d95 for more information.
 MIN_UPSTREAM_TRACK_GIT_VERSION = (2, 3)
 
@@ skipping 897 matching lines @@
                       ['HEAD'])
 
 
 def clone_file(repository, new_workdir, link, operation):
   if not os.path.exists(os.path.join(repository, link)):
     return
   link_dir = os.path.dirname(os.path.join(new_workdir, link))
   if not os.path.exists(link_dir):
     os.makedirs(link_dir)
   operation(os.path.join(repository, link), os.path.join(new_workdir, link))