Subject: bug#71367: 30.0.50; ELPA package breadcrumb causes Emacs freeze when editing json file

From: Tassilo Horn <[email-masked]>
Date: Wed, 05 Jun 2024 09:24:21 +0200

Andrea Corallo <[email-masked]> writes:

Hi Andrea,

>> I currently have no emacs without native compilation handy so I
>> cannot tell if that's important, too.  Can I somehow tell emacs not
>> to compile breadcrumb natively after deleting the eln file?
>
> yes, you can globally set 'native-comp-jit-compilation' to nil or be
> more selective on the files you don't want to be compiled using
> 'native-comp-jit-compilation'.

Ok, now I tested with

  emacs -Q --load ~/[email-masked]

where the recipe is:

--8<---------------cut here---------------start------------->8---
(progn
  ;; Native compile doesn't make a difference...
  (setq native-comp-jit-compilation-deny-list '(".*breadcrumb.*"))
  (package-initialize)
  (package-activate 'breadcrumb)
  (breadcrumb-mode)
  ;; Using json-ts-mode is essential!
  (add-to-list 'major-mode-remap-alist '(js-json-mode . json-ts-mode))
  (find-file "~/mirrorstatus.json"))
--8<---------------cut here---------------end--------------->8---

Before firing up Emacs, I've deleted the breadcrumb ELN file.

With the above recipe, Emacs instantly freezes when the file gets
displayed.  So native compilation of breadcrumb.el is not required in
order to observe this bug.  Using json-ts-mode instead of the default
js-json-mode is, though.

Bye,
Tassilo