PlasticSoup [1] filed a deletion request for libfyba [2]: Package fails to build and hasn't since at least 2017-06-19. It appears to be an issue with changes to gcc. Perhaps using an old version from the AUR could fix the issue but there has been very little interest shown in this package and upstream has been inactive for almost 9 years.
[1] https://aur.archlinux.org/account/PlasticSoup/ [2] https://aur.archlinux.org/pkgbase/libfyba/
