Stashing is also an option when copy is dirty for upload

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 732 matching lines @@
 
 def get_dirty_files():
   # Make sure index is up-to-date before running diff-index.
   run_with_retcode('update-index', '--refresh', '-q')
   return run('diff-index', '--name-status', 'HEAD')
 
 
 def is_dirty_git_tree(cmd):
   dirty = get_dirty_files()
   if dirty:
-    print 'Cannot %s with a dirty tree. You must commit locally first.' % cmd
+    print 'Cannot %s with a dirty tree. '\
+          'Commit, freeze or stash your changes first.' % cmd
     print 'Uncommitted files: (git diff-index --name-status HEAD)'
     print dirty[:4096]
     if len(dirty) > 4096: # pragma: no cover
       print '... (run "git diff-index --name-status HEAD" to see full output).'
     return True
   return False
 
 
 def status():
   """Returns a parsed version of git-status.
@@ skipping 238 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))