diff -r fbb2eddea4d2 -r 41ae9b3cbfb9 mercurial/hgweb/webutil.py
--- a/mercurial/hgweb/webutil.py	Sun Jun 10 12:24:53 2018 +0900
+++ b/mercurial/hgweb/webutil.py	Mon Mar 19 00:16:12 2018 +0900
@@ -717,6 +717,12 @@
         key = templateutil.unwrapvalue(context, mapping, key)
         return self._vars.get(key)
 
+    def getmin(self, context, mapping):
+        raise error.ParseError(_('not comparable'))
+
+    def getmax(self, context, mapping):
+        raise error.ParseError(_('not comparable'))
+
     def itermaps(self, context):
         separator = self._start
         for key, value in sorted(self._vars.iteritems()):