>>>> I think we should default to asynchonous operations as much as possible.
>>> If you are talking about the whole command, maybe. Does call-process
>>> automatically yield when ran in a make-thread?
>> No, it doesn't.  And it's threads that yield, not Emacs primitives.  A
>> thread will yield when it calls some API that invokes pselect.
> Thanks. I guess what I’m asking is that if I run the command in make-thread,
> will the thread yield when it’s waiting for the subprocess? I tried it and
> it still blocks Emacs so I guess the answer is no. But maybe I’m doing
> it wrong.

No, indeed by "asynchronous" I wasn't thinking of using threads, but
rather using `start-process` and then putting the "rest" into its
sentinel.

It's rather cumbersome to do, admittedly.
I have a work-in-progress library of "promises/futures" for Emacs which
should (eventually) make it easier, but that's not an option for the
`emacs-29` branch :-(


        Stefan