patch 8.2.2846: Vim9: "echo Func()" does not give an error for using void Commit: https://github.com/vim/vim/commit/68db996b621b98066fb7ab7028ed5c6aaa3954a8 Author: Bram Moolenaar <Bram@vim.org> Date: Sun May 9 23:19:22 2021 +0200 patch 8.2.2846: Vim9: "echo Func()" does not give an error for using void Problem: Vim9: "echo Func()" does not give an error for a function without a return value. Solution: Give an error. Be more specific about why a value is invalid.

" For Yiddish capitals should not be checked.  But only change the
" 'spellcapcheck' option when it is not at its default value.
let s:spc = &l:spc
setlocal spc&
if s:spc == &l:spc
  setlocal spc=
else
  let &l:spc = s:spc
endif
unlet s:spc