RE: Ediff error -- Permission denied (Win8)

[Drew Adams]

> After installing cygwin I tried Ediff, I got a new warning
> cygwin warning:
>   MS-DOS style path detected: d:\Temp\Macro1.txt
>   Preferred POSIX equivalent is: /cygdrive/d/Temp/Macro1.txt
>   CYGWIN environment variable option "nodosfilewarning" turns off this
> warning.
>   Consult the user's guide for more details about POSIX paths:
>     http://cygwin.com/cygwin-ug-net/using.html#using-pathnames
> 
> I tried to figure out what to do, but I don't know how to set up the
> environment variable.

Recent Cygwin did this nastiness to you (us).  You need to do this in
your init file or similar, to tell Cygwin "Hands off!":

 (setenv "CYGWIN" "nodosfilewarning")

I also added that to `setup-cygwin.el', in case you want to use that:
http://www.emacswiki.org/emacs-en/download/setup-cygwin.el

(Cygwin folks apparently don't like this...  See Emacs bug #14541:
http://debbugs.gnu.org/cgi/bugreport.cgi?bug=14541)

HTH.