swarming-cipd: fix for Windows

client/cipd.py

 # Copyright 2016 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 """Fetches CIPD client and installs packages."""
 
 __version__ = '0.1'
 
 import contextlib
 import hashlib
@@ skipping 377 matching lines @@
       logging.info('Fetching CIPD client %s:%s', package_name, instance_id)
       fetch_url = get_client_fetch_url(
           service_url, package_name, instance_id, timeout=timeoutfn())
       _fetch_cipd_client(instance_cache, instance_id, fetch_url, timeoutfn)
 
     # A single host can run multiple swarming bots, but ATM they do not share
     # same root bot directory. Thus, it is safe to use the same name for the
     # binary.
     binary_path = unicode(os.path.join(cache_dir, 'cipd' + EXECUTABLE_SUFFIX))
     if fs.isfile(binary_path):
+      # Ensure file is writable to delete the hardlink. This is important on
+      # Windows. Note that mode is stored on file node, not the hardlink, so
+      # keep it executable.
+      fs.chmod(0711, binary_path)

[M-A Ruel, 2016/06/14 18:17:46]

file_path.try_remove() does it automatically.

[nodir, 2016/06/14 22:16:05]

Done.

       fs.unlink(binary_path)
     instance_cache.hardlink(instance_id, binary_path, 0511)  # -r-x--x--x
 
     yield CipdClient(binary_path)