diff -r d5137c00ab17 -r 52034c42c09d mercurial/revlogutils/__init__.py
--- a/mercurial/revlogutils/__init__.py	Wed Dec 15 14:50:07 2021 +0100
+++ b/mercurial/revlogutils/__init__.py	Tue Dec 14 23:56:38 2021 +0100
@@ -12,6 +12,7 @@
 
 # See mercurial.revlogutils.constants for doc
 COMP_MODE_INLINE = 2
+RANK_UNKNOWN = -1
 
 
 def offset_type(offset, type):
@@ -34,6 +35,7 @@
     sidedata_offset=0,
     sidedata_compressed_length=0,
     sidedata_compression_mode=COMP_MODE_INLINE,
+    rank=RANK_UNKNOWN,
 ):
     """Build one entry from symbolic name
 
@@ -56,6 +58,7 @@
         sidedata_compressed_length,
         data_compression_mode,
         sidedata_compression_mode,
+        rank,
     )