diff -r bc138f2a2e47 -r f58a13c52726 mercurial/debugcommands.py
--- a/mercurial/debugcommands.py	Mon May 03 12:20:35 2021 +0200
+++ b/mercurial/debugcommands.py	Mon May 03 12:20:45 2021 +0200
@@ -2972,8 +2972,8 @@
             )
         return 0
 
-    v = r.version
-    format = v & 0xFFFF
+    format = r._format_version
+    v = r._format_flags
     flags = []
     gdelta = False
     if v & revlog.FLAG_INLINE_DATA: