MarsSeed [1] filed a deletion request for buttersink-git [2]: Discontinued Python2 based backup synchronizer using Amazon S3.
But defunct at least since 2018, because even at that time the Python2-based boto library didn't support most Amazon S3 functionality. Better to delete this obsolete package. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/buttersink-git/
