--- trac/ticket/templates/report_view.html.orig	2021-05-09 23:08:49 UTC
+++ trac/ticket/templates/report_view.html
@@ -162,6 +162,7 @@ history and logs, available at https://trac.edgewall.o
         # for value_for_group, row_group in row_groups:
         #   if loop.first:
         
+          #   set header_group, header = None, None
           #   set column_headers
           #     for header_group in header_groups: