MarsSeed [1] filed a deletion request for mate-session-manager-gtk2 [2]: Broken, EOL gtk2 version from 2016. FTBFS. Not compatible with current Arch Linux and the Mate desktop packages in repo.
[1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/mate-session-manager-gtk2/
