--- a/scripts/release/error.py	Sat Mar 14 00:12:22 2009 +0000
+++ b/scripts/release/error.py	Sat Mar 14 03:49:16 2009 +0000
@@ -20,3 +20,11 @@
 
 class Error(Exception):
   """Base class for release script exceptions."""
+
+
+class ObstructionError(Error):
+  """An operation was obstructed by existing data."""
+
+
+class ExpectationFailed(Error):
+  """An unexpected state was encountered by an automated step."""