Firstly, try running
pacman -Syy, then try to install sudo again.
Check that the repositories are uncommented in
Or your mirrorlist might be outdated: Generate a current list of mirrors and copy it to
Quoting from this relevant forum thread:
- pick another mirror
- try using an http mirror, not an ftp one (pick http mirror from the mirrorlist).
Alternatively you can manually download the databases with:
move them to /var/lib/pacman/sync/ and run 'pacman -Syu' again. If
you find any *.part files in /var/lib/pacman/sync/ e.g.
/var/lib/pacman/sync/core.db.part - remove them.
To prevent having problems like these it is critical to understand pacman. To learn more about using pacman, see the ArchWiki pacman article, and consult