I'm sorry. The attached patch should fix the problem. I'm not sure about the 
commit message, since I also modified html-ts-mode.

I recompiled emacs without the grammars and the warning problem shows up for 
other major modes as well.

Vincenzo


In data domenica 30 marzo 2025 08:41:12 Ora legale dell’Europa centrale, Juri 
Linkov ha scritto:
> > --- a/lisp/textmodes/mhtml-ts-mode.el
> > +++ b/lisp/textmodes/mhtml-ts-mode.el
> > @@ -50,13 +50,23 @@
> > 
> >  ;;; Code:
> >  
> >  (require 'treesit)
> > 
> > -(require 'html-ts-mode)
> > 
> >  (require 'css-mode) ;; for embed css into html
> >  (require 'js) ;; for embed javascript into html
> 
> This change broke loading of mhtml-ts-mode:
> 
> 0. emacs -Q
> 1. visit an html file
> 2. M-x mhtml-ts-mode
> 
> Debugger entered--Lisp error: (void-variable
> html-ts-mode--treesit-font-lock-feature-list) (defvar
> mhtml-ts-mode--treesit-font-lock-feature-list ...)
>   command-execute(mhtml-ts-mode record)
>   execute-extended-command(nil "mhtml-ts-mode" nil)
>   funcall-interactively(execute-extended-command nil "mhtml-ts-mode" nil)
>   command-execute(execute-extended-command)