--- a/mercurial/error.py	Sun Jan 11 23:04:24 2009 -0600
+++ b/mercurial/error.py	Mon Jan 12 10:42:31 2009 -0600
@@ -27,3 +27,9 @@
 
 class ParseError(Exception):
     """Exception raised on errors in parsing the command line."""
+
+class RepoError(Exception):
+    pass
+
+class CapabilityError(RepoError):
+    pass