Re: master 2c79a8f 2/2: Use posix_spawn if possible.

[Alan Third]

On Fri, Oct 29, 2021 at 06:46:47PM +0900, YAMAMOTO Mitsuharu wrote:
> According to the vfork man page below on macOS 12.0 released this
> week, it is deprecating vfork.
> 
>                                    YAMAMOTO Mitsuharu
>                               mituharu@math.s.chiba-u.ac.jp
> 
> NAME
>      vfork – deprecated system call to create a new process
> 
> SYNOPSIS
>      #include <unistd.h>
> 
>      pid_t
>      vfork(void);
> 
> DESCRIPTION
>      The vfork system call can be used to create new processes. As of macOS
>      12.0, this system call behaves identically to the fork(2) system call,
>      except without calling any handlers registered with pthread_atfork(2).
> 
>      This system call is deprecated. In a future release, it may begin to 
> return
>      errors in all cases, or may be removed entirely.  It is extremely 
> strongly
>      recommended to replace all uses with fork(2) or, ideally, posix_spawn(3).

Ugh, so this completely undoes the work we did to improve process
spawning performance in Emacs 26.
-- 
Alan Third