install-pacman.sh

#!/bin/bash

tar -C / -pxf pacman-5.0.1.6403.520736d-1-x86_64.pkg.tar etc usr var
tar -C / -pxf pacman-mirrors-20160112-1-any.pkg.tar      etc
tar -C / -pxf msys2-keyring-r9.397a52e-1-any.pkg.tar     usr
pacman-key --init
pacman-key --populate msys2

# add installed packages to pacman db
# full list: https://github.com/git-for-windows/git-sdk-64/tree/master/var/lib/pacman/local
pacman -Sy --dbonly msys2-runtime bash perl gnupg libutil-linux

List-installed-MSYS2-PKG.sh

#!/bin/sh
# Determine which packages exist in the current MSYS2 environment
# Intended to be used in Git-for-Windows

export OUTDIR=$PWD
wget http://repo.msys2.org/msys/x86_64/msys.files.tar.gz
mkdir -p pacman-local msys-files
tar -xf msys.files.tar.gz -C msys-files
function file2pkg () {
  # Find the corresponding package folder and move it to $PWD/pacman-local/
  # the first match wins
  F=$(grep -Fls "$1" msys-files/*/files | head -n 1)
  [ "$F" != "" ] && ( mv $(dirname "$F") "$OUTDIR/pacman-local/" && echo $F is moved )
}
export -f file2pkg

find /usr/bin/ -type f -exec bash -c 'file2pkg usr/bin/$(basename "{}")' \;
find /mingw64/bin/ -type f -exec bash -c 'file2pkg usr/bin/$(basename "{}")' \;