MarsSeed [1] filed a deletion request for firefox-extension- enhancedsteam [2]: Package is dead as per @polyzen's AUR comment from 2019-10-06 (source 404, no longer hosted by addons.mozilla.org). [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/firefox-extension-enhancedsteam/