referring to: phabricator.kde.org/D22638 - there is no such header as kfileutils.h
Have you included the patch D22620 [1] for KCoreAddons? [1] https://phabricator.kde.org/D22620
Ah! It is mantained, actually, in KCoreAddons, not in KIO itself. Thank you for pointing me to the right direction. Changing the 'Product' field, and closing as invalid.