Subject: bug#23331: 25.0.92; Cannot create temporary file ending in a period on OS X

From: Eli Zaretskii <[email-masked]>
Date: Thu, 21 Apr 2016 19:47:04 +0300

> From: John Wiegley <[email-masked]>
> Date: Thu, 21 Apr 2016 09:30:40 -0700
> 
> I'm not sure if this is a Mac problem, or an Emacs 25 problem, but it occurs
> with the latest emacs-25 on OS X 10.10:
> 
>     M-: (make-temp-name "index.magit.") RET
> 
> Will report the error:
> 
>     Cannot create temporary name for prefix: Bad file descriptor, index.magit.

Works like a charm on MS-Windows and GNU/Linux, FWIW.

Can you step with a debugger through the relevant C code?