depot_tools: add debug logic to bot_update for gerrit patches

recipe_modules/bot_update/resources/bot_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.
 
 # TODO(hinoka): Use logging.
 
 import cStringIO
 import codecs
 import collections
@@ skipping 1117 matching lines @@
 
   # Only try once, since subsequent failures hide the real failure.
   try:
     call(*cmd, tries=1)
   except SubprocessFailed as e:
     raise PatchFailed(e.message, e.code, e.output)
 
 def apply_gerrit_ref(gerrit_repo, gerrit_ref, root, gerrit_reset):
   gerrit_repo = gerrit_repo or 'origin'
   assert gerrit_ref
+  print '===Applying gerrit ref==='
+  print 'Repo is %r, ref is %r, root is %r' % (gerrit_repo, gerrit_ref, root)
   try:
     base_rev = git('rev-parse', 'HEAD', cwd=root).strip()
     git('retry', 'fetch', gerrit_repo, gerrit_ref, cwd=root, tries=1)
     git('checkout', 'FETCH_HEAD', cwd=root)
     if gerrit_reset:
       git('reset', '--soft', base_rev, cwd=root)
   except SubprocessFailed as e:
     raise PatchFailed(e.message, e.code, e.output)
 
 def check_flag(flag_file):
@@ skipping 156 matching lines @@
   # Calling git directly because there is no way to run Gclient without
   # invoking DEPS.
   print 'Fetching Git checkout'
 
   git_ref = git_checkout(solutions, revisions, shallow, refs, git_cache_dir)
 
   patches = None
   if patch_url:
     patches = get_svn_patch(patch_url)
 
+  print '===Processing patch solutions==='
   already_patched = []
   patch_root = patch_root or ''
+  print 'Patch root is %r' % patch_root
   for solution in solutions:
+    print 'Processing solution %r' % solution['name']
     if (patch_root == solution['name'] or
         solution['name'].startswith(patch_root + '/')):
       relative_root = solution['name'][len(patch_root) + 1:]
       target = '/'.join([relative_root, 'DEPS']).lstrip('/')
+      print '  relative root is %r, target is %r' % (relative_root, target)
       if patches:
         apply_svn_patch(patch_root, patches, whitelist=[target])
         already_patched.append(target)
       elif issue:
         apply_rietveld_issue(issue, patchset, patch_root, rietveld_server,
                              revision_mapping, git_ref, apply_issue_email_file,
                              apply_issue_key_file, whitelist=[target])
         already_patched.append(target)
 
   if not buildspec:
@@ skipping 424 matching lines @@
   except Exception:
     # Unexpected failure.
     emit_flag(options.flag_file)
     raise
   else:
     emit_flag(options.flag_file)
 
 
 if __name__ == '__main__':
   sys.exit(main())