There is an issue with pecl-redis 3.1.0 and session handling, which is fixed in 3.1.1RC1 (tested with an app and nette framework). Since we drop 3.0.0, we don't have a working combination for php 7 + redis + session handling. Maybe it would be nice to add a live ebuild.
Created attachment 459460 [details] pecl-redis-3.1.1_rc1.ebuild
https://pecl.php.net/package-changelog.php?package=redis&release=3.1.1RC2
version 3.1.1_rc2 is now in the tree
Thank you