He specifically switched the license because people kept sending angry support requests for badly done distro repackages that didn’t work properly.

Arch Linux’s version literally builds his latest released code. https://aur.archlinux.org/cgit/aur.git/tree/PKGBUILD?h=duckstation-git looks relatively straightforward. It checks out Stenzek’s latest code and then does a for-loop for Stenzek’s super weird build-dependencies-linux.sh script (I would have just used a .spec file in Open Build Service but my packing background is RPM and not whatever use case that is).