Install Emacs 25.3 on Ubuntu 16.04.3 LTS

get-emacs.sh

git clone -b master git://git.sv.gnu.org/emacs.git
cd emacs/
git checkout emacs-25.3
sudo apt install --no-install-recommends texinfo
sudo apt install libgtk-3-dev libxpm-dev libjpeg8-dev libgif-dev libtiff5-dev libtinfo-dev librsvg2-dev libmagickwand-dev libacl1-dev libgnutls-dev
# Note: if you have installed Anaconda python distribution, it will
# affect how linker find libjpeg8 dynamic library files.  To resolve
# this, simply remove Anaconda directory from PATH variable.
# ./autogen.sh
# ./configure
make bootstrap
# if you wish to use clang to compile, use the following instead
# make CC=clang LDFLAGS='-fuse-ld=lld -rtlib=compiler-rt' bootstrap
make check
sudo make install

Obvious I guess but unless you 'cd emacs' sometime after line 2 and before line 10 then the make bootstrap and make check will fail.

@adamprice2 You are right. I added the cd emacs to line 2.

thanks mate