jgmdev [1] filed a deletion request for cmyktool [2]: Software seems to be abandoned and requires manual patching to build. A better alternative is https://aur.archlinux.org/packages/prepress- cyan
[1] https://aur.archlinux.org/account/jgmdev/ [2] https://aur.archlinux.org/pkgbase/cmyktool/
