Return error when error occurs by raising exception

cros_mark_as_stable.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.
 
 """This module uprevs a given package's ebuild to the next revision."""
 
 
 import fileinput
@@ skipping 297 matching lines @@
 def main(argv):
   try:
     argv = gflags.FLAGS(argv)
     if len(argv) != 2:
       _PrintUsageAndDie('Must specify a valid command')
     else:
       command = argv[1]
   except gflags.FlagsError, e :
     _PrintUsageAndDie(str(e))
 
-  package_list = gflags.FLAGS.packages.split(' ')
+  package_list = gflags.FLAGS.packages.split()
   if gflags.FLAGS.commit_ids:
-    commit_id_list = gflags.FLAGS.commit_ids.split(' ')
+    commit_id_list = gflags.FLAGS.commit_ids.split()
   else:
     commit_id_list = None
   _CheckSaneArguments(package_list, commit_id_list, command)
 
   os.chdir(_CHROMIUMOS_OVERLAYS_DIRECTORY)
 
   if command == 'clean':
     _Clean()
   elif command == 'commit':
     work_branch = _GitBranch(_STABLE_BRANCH_NAME)
     work_branch.CreateBranch()
     if not work_branch.Exists():
       generate_test_report.Die('Unable to create stabilizing branch in %s' %
                                _CHROMIUMOS_OVERLAYS_DIRECTORY)
     index = 0
     try:
       for index in range(len(package_list)):
         # Gather the package and optional commit id to work on.
         package = package_list[index]
         commit_id = ""
         if commit_id_list:
           commit_id = commit_id_list[index]
 
         _Print('Working on %s' % package)
         worker = EBuildStableMarker(_EBuild(package, commit_id))
         worker.RevEBuild(commit_id)
         worker.CommitChange(_GIT_COMMIT_MESSAGE % (package, commit_id))
 
     except (OSError, IOError), e:
-      print ('An exception occurred %s\n'
+      print ('An exception occurred\n'
              'Only the following packages were revved: %s\n'
              'Note you will have to go into %s'
              'and reset the git repo yourself.' %
-             (e, package_list[:index], _CHROMIUMOS_OVERLAYS_DIRECTORY))
+             (package_list[:index], _CHROMIUMOS_OVERLAYS_DIRECTORY))
+      raise e
   elif command == 'push':
     _PushChange()
 
 
 if __name__ == '__main__':
   main(sys.argv)