(For Debian distributions with deb-src added) Download, setup and build Emacs from Savannah.

build_setup_emacs.sh

#!/usr/bin/sh

$INITAL_PWD=    #todo

# Install binary and source dependencies
sudo apt-get install build-essential checkinstall git-core ccache
sudo apt-get build-dep emacs24

# Install git-merge-changelog
git clone --depth 1 git://git.savannah.gnu.org/gnulib.git
$GNULIB_DIR #TODO
cd $GNULIB_DIR
./gnulib-tool --create-testdir --dir=/tmp/gmerge git-merge-changelog
cd /tmp/gmerge
./configure
make
sudo make -j 8 install

# Remove git-merge-changelog sources
rm -rf $GNULIB_DIR

# Grab Emacs
cd $INITIAL_PWD
git clone --depth 1 git://git.sv.gnu.org/emacs.git
cd emacs

# Make changes to gitconfig and gitattributes locally

# Build Emacs
./autogen.sh
# TODO Detect if GCC 4.8 or later
echo "[$0] Detecting if GCC 4.8 or later is present..."
./autogen.sh
./configure CFLAGS='$CFLAGS'
make -j 8

cd src
echo "[$0] Done! Run gdb -tui --args emacs -Q to start debugging Emacs..."