diff --git a/mercurial/context.py b/mercurial/context.py
--- a/mercurial/context.py
+++ b/mercurial/context.py
@@ -442,7 +442,7 @@ def _filterederror(repo, changeid):
         # If the changeset is obsolete, enrich the message with the reason
         # that made this changeset not visible
         if ctx.obsolete():
-            msg = obsutil._getfilteredreason(unfilteredrepo, changeid, ctx)
+            msg = obsutil._getfilteredreason(repo, changeid, ctx)
         else:
             msg = _("hidden revision '%s'") % changeid
 
diff --git a/mercurial/obsutil.py b/mercurial/obsutil.py
--- a/mercurial/obsutil.py
+++ b/mercurial/obsutil.py
@@ -875,10 +875,10 @@ filteredmsgtable = {
                                   "%d more"),
 }
 
-def _getfilteredreason(unfilteredrepo, changeid, ctx):
+def _getfilteredreason(repo, changeid, ctx):
     """return a human-friendly string on why a obsolete changeset is hidden
     """
-    successors = successorssets(unfilteredrepo, ctx.node())
+    successors = successorssets(repo, ctx.node())
     fate = _getobsfate(successors)
 
     # Be more precise in case the revision is superseded