c96fae7bb4f568ca [1] filed a deletion request for libz [2]: project no longer maintained. it's a drop-in replacement for zlib that follows upstream and removes some legacy cruft. it's fallen behind upstream for several versions now, including missing out on several security fixes. speaking to the maintainer on IRC, it's unlikely to be worked on in the foreseeable future as they're overwhelmed with other work. current zlib version: 1.2.11 (released Jan 2017) current libz version: 1.2.8 (released Dec 2015) [1] https://aur.archlinux.org/account/c96fae7bb4f568ca/ [2] https://aur.archlinux.org/pkgbase/libz/