MarsSeed [1] filed a deletion request for phonon-gstreamer-git [2]: Obsolete/EOL Qt5 based VCS package. Upstream repo has been archived for 2.5+ years. [a]
Arch/extra still carries the last stable release. [b] [a]: https://invent.kde.org/libraries/phonon-gstreamer [b]: https://archlinux.org/packages/?q=phonon-qt5-gstreamer [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/phonon-gstreamer-git/
