pavbaranov [1] filed a deletion request for kio_rar [2]:

This one is very old application, for KDE3.x. Package is orphaned, sources are missing (yes, I know, that it's possible to add sources from linux-apps.com), "kdebase" dependencies package isn't in repository or even in AUR. Then there isn't possible to build this package in current Arch system.

[1] https://aur.archlinux.org/account/pavbaranov/ [2] https://aur.archlinux.org/pkgbase/kio_rar/