diff --git a/contrib/debugshell.py b/contrib/debugshell.py
--- a/contrib/debugshell.py
+++ b/contrib/debugshell.py
@@ -20,6 +20,7 @@ def ipdb(ui, repo, msg, **opts):
 
     cl = repo.changelog
     mf = repo.manifest
+    cl, mf # use variables to appease pyflakes
 
     IPython.embed()