Day 3 of trying to set up a VM for this legacy app. Demotivation is at an all-time high.

Kek

At least you're persistent. Keep it up 👍👍

I feel your pain. Currently maintaining an intranet for a large bank and we're migrating to a new server this weekend. One query that worked OK in my Debian Jessie VM didn't work in production. In the end it turned out that the production server still ran MySQL 5.0, which I couldn't find packages for. Fortunately a move to a new server was imminent so this weekend we're moving it to MariaDB 10.2 and going from PHP 5.4 to 5.6.