We're going through all games in the Steam Linux catalog to ensure they are compatible with our new GL tracer/debugger toolset (VOGL). But this is backwards looking: what we really want is to ensure our full-stream tracing and state snapshot/restore code is compatible and correct with your new (most likely unreleased) GL code.
So if you would like to help right now, please use apitrace (on any "big" GL platform: Linux/OSX/Windows) to make a 30-90 second trace of your app's gameplay:https://github.com/apitrace/apitrace
The more representative the trace is of your actual (end-user) GL usage, the better. We're especially interested in advanced GL 3.x/4.x usage patterns, or any new extensions you use. We'll add your trace to our private correctness and regression testing repo. We'll replay your trace, capture it with our tools, and take it from there.
E-mail me (richg at valvesoftware dot com) with the location, or for very large traces that are too big for dropbox, etc. we'll set you up a private FTP site.
Also, if your game is already on Steam Linux and you're actively debugging GL issues I can move your app to the top of the testing list.