This is a over-engineered bash script to update PKGBUILD and .SRCINFO for my user submitted and user maintained pkgbuild for Allusion Appimage.
This is not an official installer and it is not maintained by the developers of Allusion.
You can find the offical github repository for Allusion App here: allusion-app/Allusion
This package can be found on the Arch Linux User Repository (AUR) here: allusion-appimage