bug#31144: cygwin bash: cannot set terminal process group (-1): inappropriate ioctl for device

[Eli Zaretskii]

> From: Piyush Kapadia <piyush_kapadia@hotmail.com>
> Date: Fri, 13 Apr 2018 02:00:45 +0000
> 
> There is a bug out there for using NTEmacs on Windows.
> 
> NTEmacs on Windows is great setup to use in combination with cygwin.
> 
> However since quite some time when you launch cygwin as a shell from NTEmacs 
> it give this error.
> 
> There is a bug out there for using NTEmacs on Windows.
> 
> Its been several years and no one has been able to solve it yet.
> 
> Please look through this and solve it so that cygwin could be used as a shell 
> from with in NTEmacs.

I see no such error message in Emacs sources.  Unless I missed
something, this means the error message comes from Cygwin, and you
should first report this problem on the Cygwin mailing list.  If the
analysis of the Cygwin developers concludes that this is something
that should be fixed in Emacs, and indicates how to do that, please
come back here with those conclusions, and we will try to see how to
fix this.

Also, you didn't say which version of Emacs you are using, and where
did you get the binaries, if you didn't yourself compile Emacs.  If
your version of Emacs is old, I suggest to try the latest version (RC1
of Emacs 26.1 was just released and is available from alpha.gnu.org),
because it's possible the problem was solved in the meantime.

P.S.  In general, the combination of the native Windows build of Emacs
and Cygwin tools is only semi-supported, as there are subtle
incompatibilities between them.  You may be better off using the
Cygwin build of Emacs, either the one that requires X libraries or the
one that uses the native w32 widgets.

Thanks.