Make git-freeze bail out if the user has too much untracked data.

git_rebase_update.py

 #!/usr/bin/env python
 # 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.
 
 """
 Tool to update all branches to have the latest changes from their upstreams.
 """
 
 import argparse
 import collections
 import logging
 import sys
 import textwrap
 
 from pprint import pformat
 
 import git_common as git
 
 
 STARTING_BRANCH_KEY = 'depot-tools.rebase-update.starting-branch'
 
 
 def find_return_branch():
   """Finds the branch which we should return to after rebase-update completes.
 
   This value may persist across multiple invocations of rebase-update, if
   rebase-update runs into a conflict mid-way.
   """
-  return_branch = git.config(STARTING_BRANCH_KEY)
+  return_branch = git.get_config(STARTING_BRANCH_KEY)
   if not return_branch:
     return_branch = git.current_branch()
     if return_branch != 'HEAD':
       git.set_config(STARTING_BRANCH_KEY, return_branch)
 
   return return_branch
 
 
 def fetch_remotes(branch_tree):
   """Fetches all remotes which are needed to update |branch_tree|."""
@@ skipping 201 matching lines @@
           % (return_branch, root_branch)
         )
       git.run('checkout', root_branch)
     git.set_config(STARTING_BRANCH_KEY, '')
 
   return retcode
 
 
 if __name__ == '__main__':  # pragma: no cover
   sys.exit(main(sys.argv[1:]))