Subject: Re: bug#78946: 30.1; accept-process-output not allowed in threads on macOS

From: "J.D. Smith" <[email-masked]>
Date: Sun, 06 Jul 2025 15:12:31 -0400

John Wiegley <[email-masked]> writes:

> If I run the attached code from the terminal using:
>
> #+begin_src sh
> emacs -batch -Q -l accept-process-bug.el
> #+end_src
>
>
> It will correctly run forever, processing output from the “yes” command (you
> can convince yourself of this by adding a debug statement inside the process
> filter, but it will be extremely noisy).
>
> If you now attempt to evaluate this code in a graphical Emacs running on
> macOS, it will immediately stall out. Running Emacs under lldb shows that it
> is reporting the following exception continuously:
>

FYI, the emacs-mac build does not suffer this problem.  It runs until you C-g, reporting:

    Starting thread...
    Beginning yield loop...
    Joining thread...
    Test completed!