diff -r bc2519513ae0 -r f63299ee7e4d mercurial/manifest.py
--- a/mercurial/manifest.py	Fri Feb 19 10:53:27 2021 +0100
+++ b/mercurial/manifest.py	Wed Mar 10 19:33:18 2021 +0100
@@ -1610,6 +1610,7 @@
         self.index = self._revlog.index
         self.version = self._revlog.version
         self._generaldelta = self._revlog._generaldelta
+        self._revlog.revlog_kind = b'manifest'
 
     def _setupmanifestcachehooks(self, repo):
         """Persist the manifestfulltextcache on lock release"""