--- a/mercurial/revlogutils/flagutil.py	Wed Sep 04 03:19:58 2019 +0200
+++ b/mercurial/revlogutils/flagutil.py	Wed Sep 04 03:20:55 2019 +0200
@@ -17,6 +17,7 @@
     REVIDX_FLAGS_ORDER,
     REVIDX_ISCENSORED,
     REVIDX_RAWTEXT_CHANGING_FLAGS,
+    REVIDX_SIDEDATA,
 )
 
 from .. import (
@@ -29,6 +30,7 @@
 REVIDX_ISCENSORED
 REVIDX_ELLIPSIS
 REVIDX_EXTSTORED
+REVIDX_SIDEDATA
 REVIDX_DEFAULT_FLAGS
 REVIDX_FLAGS_ORDER
 REVIDX_RAWTEXT_CHANGING_FLAGS