When updating archlinux using:
sudo pacman -Syu
I sometimes get an error message that looks something like this:
error: zstd: signature from "Andrzej Giniewicz (giniu) <randomemail@gmail.com>" is marginal trust
:: File /var/cache/pacman/pkg/zstd-1.3.2-1-x86_64.pkg.tar.xz is corrupted (invalid or corrupted package (PGP …