kmille [1] filed a deletion request for fprint_demo-git [2]: https://fprint.freedesktop.org/ says: fprint_demo is obsolete. Most features are integrated into fprintd’s helpers, and libfprint has an examples section. You can use https://aur.archlinux.org/packages/fprint_demo which links to an older/working version of libfprint. This package can be removed. [1] https://aur.archlinux.org/account/kmille/ [2] https://aur.archlinux.org/pkgbase/fprint_demo-git/