MarsSeed [1] filed a deletion request for mautrix-hangouts-git [2]: Discontinued and terminally broken, as Google has shut down the relevant Hangouts service and its API access points.
Upstream has been renamed and repurposed as https://aur.archlinux.org/packages/mautrix-googlechat [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/mautrix-hangouts-git/
