Don't use 'git remote get-url', which is a new-ish feature.

git_cl.py

 #!/usr/bin/env python
 # 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.
 
 # Copyright (C) 2008 Evan Martin <martine@danga.com>
 
 """A git-command for integrating reviews on Rietveld."""
 
 from distutils.version import LooseVersion
@@ skipping 613 matching lines @@
   def GetRelativeRoot():
     return RunGit(['rev-parse', '--show-cdup']).strip()
 
   def GetRoot(self):
     if self.root is None:
       self.root = os.path.abspath(self.GetRelativeRoot())
     return self.root
 
   def GetGitMirror(self, remote='origin'):
     """If this checkout is from a local git mirror, return a Mirror object."""
-    local_url = RunGit(['remote', 'get-url', remote]).strip()
+    local_url = RunGit(['config', '--get', 'remote.%s.url' % remote]).strip()
     if not os.path.isdir(local_url):
       return None
     git_cache.Mirror.SetCachePath(os.path.dirname(local_url))
     remote_url = git_cache.Mirror.CacheDirToUrl(local_url)
     # Use the /dev/null print_func to avoid terminal spew in WaitForRealCommit.
     mirror = git_cache.Mirror(remote_url, print_func = lambda *args: None)
     if mirror.exists():
       return mirror
     return None
 
@@ skipping 3338 matching lines @@
 if __name__ == '__main__':
   # These affect sys.stdout so do it outside of main() to simplify mocks in
   # unit testing.
   fix_encoding.fix_encoding()
   colorama.init()
   try:
     sys.exit(main(sys.argv[1:]))
   except KeyboardInterrupt:
     sys.stderr.write('interrupted\n')
     sys.exit(1)