Install MacPorts in /opt/macports from sources.

install-macports-from-sources.sh

#!/usr/bin/env bash

if [[ ${DEBUG} != "" ]]; then
  set -x 
fi

set -o errexit 
set -o pipefail 
set -o nounset 

IFS=$'\n\t'

# https://gist.github.com/ilg-ul/383869cbb01f61a51c4d
# ----------------------------------------------------------------------------

# https://guide.macports.org/chunked/installing.macports.html

MP_VERSION="2.3.4"
MP_PREFIX="/opt/macports"
MP_BUILD_FOLDER="~/Work/MacPorts"

mkdir -p "${MP_BUILD_FOLDER}"
cd "${MP_BUILD_FOLDER}"

rm -rf "MacPorts-${MP_VERSION}"
curl "https://distfiles.macports.org/MacPorts/MacPorts-${MP_VERSION}.tar.bz2" | tar -x -v -f -
cd MacPorts-${MP_VERSION}

# Play safe, exclude possible trouble sources from PATH.
export PATH=/bin:/sbin:/usr/bin:/usr/sbin
./configure --prefix="${MP_PREFIX}"
make

echo 'Enter sudo password'
# Potentially dangerous!
sudo rm -rf "${MP_PREFIX}"
sudo mkdir "${MP_PREFIX}"
sudo make install

export PATH="${MP_PREFIX}/bin":"${MP_PREFIX}/sbin":$PATH
sudo port -v selfupdate

# To use MacPorts, add something like this to ~/.profile
#   alias mp='export PATH=/opt/macports/bin:/opt/macports/sbin:$PATH'