After a system update, we see This version of ownCloud is not compatible with PHP 7.1. You are currently running 7.1.1. Please use at least ownCloud 10.0.0. however, there is no owncloud 10.0.0 in portage. We'll downgrade PHP for now, but it would by nice if Gentoo had 10.x Reproducible: Always
It seems 10.0.0 isn't released yet. Homepage only mentions releases up to 9.1.4: https://owncloud.org/changelog/ No release announcement in ML either: https://mailman.owncloud.org/pipermail/user/2017-February/thread.html
Well, could you at least confirm that 9.1.4 refuses to work with the newest PHP/ the error message posted is reproducible? I mean we DID end up with a broken configuration using 9.1.4 with that specific message.