Gets past broken build for --mode debug

tools/upload_sdk.py

Index: tools/upload_sdk.py
diff --git a/tools/upload_sdk.py b/tools/upload_sdk.py
index 049d89fdd5f6182d31918b4330b3bb0cd8921db2..6bad855046b5b3a62b3a5d61dd12e4f7cc8a9fad 100644
--- a/tools/upload_sdk.py
+++ b/tools/upload_sdk.py
@@ -52,20 +52,26 @@ def GetSVNRevision():
       return (line.strip().split())[1]
   return None
 
+
+def usage(progname):
+    sys.stderr.write('Usage: %s path_to_sdk\n' % progname)
+
+
 def main(argv):
-  if (not os.path.exists(argv[1])):
-    sys.stderr.write('Usage: upload_sdk.py path_to_sdk\n')
+  if not os.path.exists(argv[1]):
+    sys.stderr.write('Path not found: %s\n' % argv[1])
+    usage(argv[0])
     return 1
   if (not os.path.exists(GSUTIL)):
     exit(0)
   revision = GetSVNRevision()
-  if revision == None:
+  if revision is None:
     sys.stderr.write('Unable to find SVN revision.\n')
     return 1
   os.chdir(argv[1])
   # TODO(dgrove) - deal with architectures that are not ia32.
   sdk_name = 'dart-' + utils.GuessOS() + '-' + revision + '.zip'
-  sdk_file = '../' + sdk_name 
+  sdk_file = '../' + sdk_name
   ExecuteCommand(['zip', '-yr', sdk_file, '.'])
   UploadArchive(sdk_file, GS_SITE + os.path.join(GS_DIR, SDK, sdk_name))
   latest_name = 'dart-' + utils.GuessOS() + '-latest' + '.zip'