The upcoming release of Arch's Pacman 5.2 is bringing support for compressing packages with Zstd which ultimately will provide faster package installs on Arch Linux.

Similar to other Linux distributions beginning to make use of Facebook's Zstd (Zstandard) compression algorithm for faster compression/decompression of packages, Arch Linux is doing the same. Their findings mirror that of others in allowing faster compression/decompression performance with a similar compression ratio for binaries to that of XZ.

With Pacman 5.2, the Zstd package compression is being rolled out for Arch Linux while ahead of that is a bulletin today that users need a libarchive within the past year. Since September 2018 has been a libarchive on Arch Linux supporting Zstd, but if for some reason you are running an Arch Linux install with a very outdated libarchive, you will want to update soon to avoid issues moving forward.

More details on this notice via ArchLinux.org.