MarsSeed [1] filed a deletion request for libflashsupport-jack [2]: As per maintainer's comment, obsolete since 2016.
This is also a VCS package with undeclared sources. Getting the URL from PKGBUILD, I see no new commit since 2010. [a] Nothing depends on it. Maintainer pointed users in the direction of other possible solutions in last comment from 2016. [a]: https://repo.or.cz/libflashsupport-jack.git [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/libflashsupport-jack/
