It is probably an OS X only crash.

Emacs won't write the file unless if server-use-tcp is enabled. Customize it, enable server-use-tcp (set to true), save for future sessions. Restart emacs. Launch server. If the folder doesn't exist, Emacs will create it and assign 700 perms.

I've reproduced with a vanilla configuration of Emacs to rule out the possibility it is a conflict with some other extension I've installed.

Tim

On Sun, Jun 17, 2018 at 5:00 AM Alan Third <alan@idiocy.org> wrote:
On Fri, Jun 15, 2018 at 11:15:05AM -0600, Tim Harper wrote:
> Emacs on OS X crashes when stale server auth file is present. To reproduce:
>
> 1) Start Emacs 26.1
> 2) Run server-start
> 3) Copy the file `server` in the {server-auth-dir} folder to `server-2`
> 4) Quit Emacs
> 5) Rename `server-2` file to `server`
> 6) Relaunch Emacs
> 7) Run server-start
> 8) Observe crash

I’m probably being daft, but I can’t find any ‘server’ file when I’m
running the emacs server.

The directory listed in server-auth-dir doesn’t even exist.
--
Alan Third