Compatibility with php7 errors

I am using Debian 8 x64 and the dotdeb repos with php 7 RC 6 builds and the first thing I wanted to do was test your redis plugin with the pecl extension I successfully built and installed just like I have for php5. I get a 500 internal server error when I activate the plugin and the error log shows this for nginx:

Stack trace:
#0 /var/www/htpcguides/wp-content/object-cache.php(613): Redis->get('wp_:default:is_...')
#1 /var/www/htpcguides/wp-content/object-cache.php(110): WP_Object_Cache->get('is_blog_install...', '')
#2 /var/www/htpcguides/wp-includes/functions.php(1282): wp_cache_get('is_blog_install...')
#3 /var/www/htpcguides/wp-includes/load.php(472): is_blog_installed()
#4 /var/www/htpcguides/wp-settings.php(109): wp_not_installed()
#5 /var/www/htpcguides/wp-config.php(89): require_once('/var/www/htpcgu...')
#6 /var/www/htpcguides/wp-load.php(37): require_once('/var/www/htpcgu...')
#7 /var/www/htpcguides/wp-admin/admin.php(31): require_once('/var/www/htpcgu...')
#8 /var/www/htpcguides/wp-admin/plugins.php(10): require_once('/var/www/htpcgu...')
#9 {main}
  thrown in /var/www/htpcguides/wp-content/object-cache.php on line 613" while reading response header from upstream, client: 192.168.60.1, server: www.htpcguides, request: "GET /wp-admin/plugins.php?plugin_status=all&paged=1&s HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "192.168.60.134:8090"

https://wordpress.org/plugins/redis-cache/