mercurial/revset.py

--- a/mercurial/revset.py	Sun Jan 27 13:18:53 2019 +0900
+++ b/mercurial/revset.py	Sun Jan 27 13:28:45 2019 +0900
@@ -1071,7 +1071,7 @@
     fromline, toline = util.processlinerange(
         *getintrange(args['lines'][0],
                      # i18n: "followlines" is a keyword
-                     _("followlines expects a line range"),
+                     _("followlines expects a line number or a range"),
                      _("line range bounds must be integers")))
 
     fctx = repo[rev].filectx(fname)