vim9script syntax file how to deal with s:cpo_save

[Ni Va]

hi,

after migrating vim to vim9script syntax file, this one embbeded these kind of lines code :

vim9script

if exists("b:current_syntax")
  finish
endif

s:cpo_save = &cpo
set cpo&vim

so i encounter these error now :

"foobar.log" [converted] 12550L, 1485333B
Error detected while processing BufRead Autocommands for "*.log"..FileType Autocommands for "*"..Syntax Autocommands for "*"..function <SNR>19_SynSet[25]..script Z:\soft\Vim\vimfiles\syntax\log.vim:
line   11:
E1089: Unknown variable: s:cpo_save
Error detected while processing BufEnter Autocommands for "*.log"..FileType Autocommands for "*"..Syntax Autocommands for "*"..function <SNR>19_SynSet[25]..script  Z:\soft  \Vim\vimfiles\syntax\log.vim:
line   11:
E1089: Unknown variable: s:cpo_save