Script to build emacs on Mac OS

What-I-Did

#!/bin/bash -x

VERSION=emacs-26.1

if [[ ! -d /usr/local/src/${VERSION} ]] ; then
  cd /usr/local/src
  tar xf /usr/local/images/${VERSION}/${VERSION}.tar.*
fi

cd /usr/local/images/${VERSION}
image=$( ls -1 ${VERSION}-mac* | tail -1 )
base="${image%.tar.*}"
if [[ ! -d "/usr/local/src/${base}" ]] ; then
  cd /usr/local/src
  tar xf "/usr/local/images/${VERSION}/${image}"
fi

echo "Does everything look good?  If so, hit return"
read not_used

# step a.
EMACS_SOURCE_TOP=/usr/local/src/${VERSION}
# FTP from ftp://ftp.math.s.chiba-u.ac.jp/emacs
MACDIR="/usr/local/src/${base}"

cd "${EMACS_SOURCE_TOP}"

# step b.
if ! patch -p1 < $MACDIR/patch-mac ; then
  echo Patching Failed
  exit 1
fi

# steps c, f, and g.
( cd "${MACDIR}" ; tar cf - mac src lisp ) | tar xf -

# step d.
cp nextstep/Cocoa/Emacs.base/Contents/Resources/Emacs.icns \
   mac/Emacs.app/Contents/Resources/Emacs.icns 

cat << \EOF > Do-Configure
#!/bin/bash
export LDFLAGS="-L/usr/local/opt/libxml2/lib"
export CPPFLAGS="-I/usr/local/opt/libxml2/include/libxml2"
./configure --with-mac \
            --without-imagemagick \
            --enable-mac-app \
            --prefix=/Applications/Emacs.app/Contents/Resources \
            --exec_prefix=/Applications/Emacs.app/Contents/MacOS && \
    make -j10 && \
    make DESTDIR=`pwd`/root install && \
    open root
echo $?
EOF
chmod +x ./Do-Configure
./Do-Configure