Install Homebrew in /opt/homebrew.

install-homebrew.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
# ----------------------------------------------------------------------------

HB_PREFIX=${HB_PREFIX:-"/opt/homebrew"}

echo 'Enter sudo password'
sudo rm -rf "${HB_PREFIX}"

sudo mkdir -p "${HB_PREFIX}"

sudo chown -R $(whoami) "${HB_PREFIX}"
bash -c "(curl -L https://github.com/Homebrew/homebrew/tarball/master | tar -x -v --strip 1 -C "${HB_PREFIX}" -f -)"
brew --version

rm -rf "${HB_PREFIX}/share/doc/homebrew"
brew update

# To use Homebrew, add something like this to ~/.profile
echo alias hb=\'export PATH=${HB_PREFIX}/bin:\$PATH\'