I faced the same; got fixed after re-running autogen.sh.

On Wed, Jan 11, 2017 at 12:26 PM Alan Mackenzie <acm@muc.de> wrote:
Hello, Emacs.

I'm getting this error while trying to build under GNU/Linux:

    automake-1.15: error: cannot open < lib/../nt/gnulib.mk: No such file or directory
    Makefile:456: recipe for target 'lib/Makefile.in' failed

.  Doesn't *.mk belong to w32 builds?

I updated master at ~ 17:00 +0000 today.

--
Alan Mackenzie (Nuremberg, Germany).

--

Kaushal Modi