--- a/mercurial/util.py Sat Dec 06 15:40:04 2008 +0100
+++ b/mercurial/util.py Sat Dec 06 15:53:57 2008 +0100
@@ -705,7 +705,7 @@
if cwd is not None and oldcwd != cwd:
os.chdir(oldcwd)
-class SignatureError:
+class SignatureError(Exception):
pass
def checksignature(func):