When I tried to run www-apps/owncloud-9.1.3 on dev-lang/php:7.1 there was a message on the www index: This version of ownCloud is not compatible with PHP 7.1. You are currently running 7.1.0. Please use at least ownCloud 9.2.0.
Thanks for the report! Indeed they added a check in recent versions to warn users. I updated the deps in current ebuilds (until they release 9.2 which does list php7 support as a feature)
At least version 9.1.3 of ownCloud is compatible and supported with PHP version 7.0. Only PHP version 7.1 is not supported. Please adjust www-apps/owncloud-9.1.3.ebuild again.
You're right, only 8.1 has a 7.0 limitation, >= 8.2 allow it (and 9.x only error out on 7.1). Updating the deps again
Hoping I got these dependencies right this time :) Don't hesitate to reopen if that is not the case