Re: jar files won't open in emacs 27.1 on debian 11.6 "bullseye"

[Eli Zaretskii <eliz@gnu.org>]

> From: Steinar Bang <sb@dod.no>
> Date: Sun, 02 Apr 2023 17:03:20 +0200
> 
> > Step with Edebug through arc-mode.el and see why it signals the error?
> > It is possible that the jar file you tried uses some extensions of the
> > ZIP format which were not yet supported in Emacs 27, so perhaps try
> > with a later version of Emacs.
> 
> no luck with edebug so far.
> 
> I first did (setq debug-on-error t) in a fresh emacs and got the
> following stack trace from attempting to open the javadoc file:
>  https://gist.github.com/steinarb/234cf172c214b26b33ee92a4e5b5afd1
> and found archive-zip-summarize which looks promising (and is in
> arc-mode.el) 
> 
> Then I opened a new fresh emacs and openet /usr/share/emacs/27.1/lisp/arc-mode.el.gz
> and but the cursor over archive-zip-summarize and did 'C-u C-M-x'
> 
> Then I tried opening the javadoc.jar but, unfortunately it didn't stop
> in archive-zip-summarize
> 
> Not sure what more to do to make the code stop in the debugger (I have
> skimmed the edebug docs to get this far).

You need to "M-x load-file RET arc-mode.el.gz RET" before "C-u M-x" of
the function.  The Emacs will stop in the function.