FabioLolix [1] filed a deletion request for protobuf25 [2]: Old version of protobus, not usable as drop-in replacement because too old. After asking if there was programs that depends on this specific version the maintainer abandoned it.
[1] https://aur.archlinux.org/account/FabioLolix/ [2] https://aur.archlinux.org/pkgbase/protobuf25/
