It turns out qt5-websockets needs to be included for a successful build.
PKGBUILD format is described on the Arch wiki https://wiki.archlinux.org/index.php/Creating_packages Arch User Repository is described here https://wiki.archlinux.org/index.php/Arch_User_Repository The AUR package can be found here https://aur.archlinux.org/packages/ovras/