mercurial/cmdutil.py

--- a/mercurial/cmdutil.py	Sat Dec 13 19:36:50 2014 -0500
+++ b/mercurial/cmdutil.py	Sat Dec 13 19:44:55 2014 -0500
@@ -2801,7 +2801,7 @@
             if targetsubs:
                 # Revert the subrepos on the revert list
                 for sub in targetsubs:
-                    ctx.sub(sub).revert(ui, ctx.substate[sub], *pats, **opts)
+                    ctx.sub(sub).revert(ctx.substate[sub], *pats, **opts)
     finally:
         wlock.release()