diff -r 15d35f2ba474 -r e58e234096de mercurial/cmdutil.py
--- a/mercurial/cmdutil.py	Tue Jul 21 22:13:54 2020 +0200
+++ b/mercurial/cmdutil.py	Sat Aug 08 15:48:17 2020 +0530
@@ -58,6 +58,8 @@
     vfs as vfsmod,
 )
 
+from .interfaces import repository
+
 from .utils import (
     dateutil,
     stringutil,
@@ -1358,7 +1360,7 @@
         if cl:
             r = repo.unfiltered().changelog
         elif dir:
-            if b'treemanifest' not in repo.requirements:
+            if repository.TREEMANIFEST_REQUIREMENT not in repo.requirements:
                 raise error.Abort(
                     _(
                         b"--dir can only be used on repos with "