Comment 1 for bug 1264257

I think the key here is that glmark2 eschews any configs with a stencil component (because there are no scenes currently that make use of stencil buffers). So, the key line (just a few lines below the excerpt from GLVIsualConfig::match_score() you included) is the following:

    score += score_component(stencil, target.stencil, 0);

This will add '-1000' to the score for any config that has a stencil component, and thus bump it well down the list of "preferred" configs. If this is causing you problems for other reasons (e.g., the implementation in question exposes other features only in configs with a stencil component), let us know, and we can look into changing it. For your immediate purposes, if you change the '0' to a '1' in that line, you should see the behavior you are asking for.

cheers,
Jesse