If for whatever crazy reason, you want to force Linux to use a Software OpenGL implementation, simply run this command before launching your application:
I needed to do this to run Godot Engine on an old laptop that had no hardware OpenGL implementation, and it works like a charm.
One of the most important lessons that gets repeated over and over in game development is COMPLETE YOUR GAME. It deserves to be repeated again by myself. Often times it sounds easy but there are little distractions that can get in the way of actually shipping a complete game.