Hey, posting again to let people know that I did the upgrade from PHP 5.6 to PHP 7, from Debian Wheezy to Stretch (running MODx Revo 2.5.2). I had some issues, but none with MODx except this:
[Mon Sep 18 22:51:11.362790 2017] [:error] [pid 13732] [client xx.xx.xx.xx:62693] FastCGI: server "/usr/lib/cgi-bin/php-fpm7.0" stderr: PHP message: PHP Fatal error: Uncaught TypeError: Argument 2 passed to modX::getChunk() must be of the type array, string given, called in /corepath/cache/mydomain/includes/elements/modsnippet/26.include.cache.php on line 127 and defined in /corepath/model/modx/modx.class.php:1812, referer:
http://mydomain.com/somedir/?page=index.html
It was easy to fix by making sure the second arg to getChunk() is always an array. Empty/NULL strings throw this error. This didn't happen before I upgraded, so I thought I'd let you know.
Thanks again!