Oftentimes our local repository goes out of sync, and you can’t install anything unless you update pacman’s database.

One way to do this without upgrading any package is typing pacman -Sy or pacman -Syy.

• -S tells pacman you want to synchronize packages. In other words, it’s used for installing packages.
• -y will refresh (sync) all of your package lists, ensuring you have the latest version of each package available for download and installation.
• -yy forces a refresh of all package lists, even if they are considered to be up to date. This can be helpful if a mirror has not correctly updated or there is a local issue with the package database.

Use -yy sparingly though, since it has the potential to cause a huge load on the servers.