srousseau [1] filed a request to merge scout [2] into passmcp [3]: Upstream is gone: the scout repository (https://github.com/sebastienrousseau/scout) has been deleted and its release downloads no longer exist, so this package cannot build. The project continues as passmcp (https://github.com/sebastienrousseau/passmcp). I maintain this package and the upstream project.
[1] https://aur.archlinux.org/account/srousseau/ [2] https://aur.archlinux.org/pkgbase/scout/ [3] https://aur.archlinux.org/pkgbase/passmcp/
