pacman doesn’t update

Usually, it’s because of the mirrorlist. All you need to do is to update the mirrorlist according to the country you’re in. For example, if you’re in France:

$ sudo reflector --country France --sort rate --save /etc/pacman.d/mirrorlist
$ sudo pacman -Syyu

paru -Syu doesn’t work

Once and a while, you’ll see the error

paru: error while loading shared libraries: libalpm.so.15: cannot open shared object file: No such file or directory

In order to solve it, navigate to the directory you cloned paru before (or reclone again in case you forget) then

git pull
makepkg -si