--- a/mercurial/repocache.py	Thu Oct 26 05:37:37 2023 +0200
+++ b/mercurial/repocache.py	Tue Oct 24 11:08:49 2023 +0200
@@ -129,7 +129,7 @@
     srcfilecache = srcrepo._filecache
     if b'changelog' in srcfilecache:
         destfilecache[b'changelog'] = ce = srcfilecache[b'changelog']
-        ce.obj.opener = ce.obj._realopener = destrepo.svfs
+        ce.obj.opener = ce.obj._inner.opener = destrepo.svfs
     if b'obsstore' in srcfilecache:
         destfilecache[b'obsstore'] = ce = srcfilecache[b'obsstore']
         ce.obj.svfs = destrepo.svfs