Use release candidates as a backup in case we fail to find the latest release.

bin/ctest.py

 #!/usr/bin/python
 #
 # Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Wrapper for tests that are run on builders."""
 
 import fileinput
 import optparse
@@ skipping 149 matching lines @@
       latest_image_file.close()
       # Convert bin.gz into zip.
       latest_image = latest_image.replace('.bin.gz', '.zip')
       version = latest_image.split('-')[1]
       zip_base = os.path.join(zip_server_base, channel, board)
       return os.path.join(zip_base, version, latest_image)
     except IOError:
       Warning(('Could not use latest link provided, defaulting to parsing'
                ' latest from zip url base.'))
 
-  return GetNewestLinkFromZipBase(board, channel, zip_server_base)
+  try:
+    return GetNewestLinkFromZipBase(board, channel, zip_server_base)
+  except:
+    Warning('Failed to get url from standard zip base.  Trying rc.')
+    return GetNewestLinkFromZipBase(board + '-rc', channel, zip_server_base)
 
 
 def GrabZipAndExtractImage(zip_url, download_folder, image_name) :
   """Downloads the zip and extracts the given image.
 
   Doesn't re-download if matching version found already in download folder.
   Args:
     zip_url - url for the image.
     download_folder - download folder to store zip file and extracted images.
     image_name - name of the image to extract from the zip file.
@@ skipping 113 matching lines @@
                    options.remote)
 
 
 if __name__ == '__main__':
   try:
     main()
   except Exception:
     print "Got exception."
     traceback.print_exc(file=sys.stdout)