diff --git a/mercurial/changegroup.py b/mercurial/changegroup.py
--- a/mercurial/changegroup.py
+++ b/mercurial/changegroup.py
@@ -804,10 +804,10 @@
                 # We failed to resolve a parent for this node, so
                 # we crash the changegroup construction.
                 if util.safehasattr(store, 'target'):
-                    target = store._indexfile
+                    target = store.display_id
                 else:
                     # some revlog not actually a revlog
-                    target = store._revlog._indexfile
+                    target = store._revlog.display_id
 
                 raise error.Abort(
                     b"unable to resolve parent while packing '%s' %r"
diff --git a/tests/test-narrow-pull.t b/tests/test-narrow-pull.t
--- a/tests/test-narrow-pull.t
+++ b/tests/test-narrow-pull.t
@@ -147,7 +147,7 @@
   $ hg clone -q --narrow ssh://user@dummy/master narrow2 --include "f1" -r 0
   $ cd narrow2
   $ hg pull -q -r 1
-  remote: abort: unexpected error: unable to resolve parent while packing '00manifest.i' 1 for changeset 0
+  remote: abort: unexpected error: unable to resolve parent while packing '00manifest' 1 for changeset 0
   transaction abort!
   rollback completed
   abort: pull failed on remote