"Git for Windows SDK" is 5.33GB compared to "Git for Windows" 691MB compared to "Portable Git" 275MB. I use the lean and mean Portable Git. At first, it seems hopeless trying to restore and use pacman in the latter two flavors of Git (msys2), because Google excluded ALL metadata files in /var/lib/pacman/local. Please read this official explanation:
https://wiki.archlinux.org/index.php/Pacman#.22Failed_to_commit_transaction_.28conflicting_files.29.22_error
Without those metadata files, you don't know the exact collection and version of the msys2 packages Google selected to build a release of those 2 flavors of Git. If you force to install or copy the current version of msys2 packages, you run the risk of version mismatch with git binaries Google built and tested.
Well, that's until I discover this file: /etc/package-versions.txt, the laundry list of matching msys2 packages and versions. Now there is a definitive source in github. Here is how I restore pacman in Portable Git:
Step 1: Go to msys2 to download 3 packages: pacman, pacman-mirrors and msys2-keyring. Click the "File:" link of each package.
Step 2: Unpack them at the root then restore pacman with these commands:
cd /
tar x --xz -vf ~/Downloads/msys2-keyring-1~20201002-1-any.pkg.tar.xz usr
tar x --xz -vf ~/Downloads/pacman-mirrors-20201028-1-any.pkg.tar.xz etc
tar x --xz -vf ~/Downloads/pacman-5.2.2-4-x86_64.pkg.tar.xz usr
pacman-key --init
pacman-key --populate msys2
pacman -Syu
Step 3: The next two commands restore all matching metadata. The second command is multi-line but still safe to cut and paste (be patient):
URL=https://github.com/git-for-windows/git-sdk-64/raw/main
cat /etc/package-versions.txt | while read p v; do d=/var/lib/pacman/local/$p-$v;
mkdir -p $d; for f in desc files install mtree; do curl -sSL "$URL$d/$f" -o $d/$f;
done; done
Step 4: Now, is it too much to ask for 'make' and 'zip'?
pacman -S make zip
Voilà, still just a 337MB mean little environment that can expand and upgrade!