Penumbra loads, but screen goes blank.

[niadh]

It is on game start up, as soon as the game begins to load the screen goes blank.

Can you suggest a game that might have the same effect, assuming the issue is with mesa gl?

I tried gnu/chess using the opengl back end and it worked in both windowed and full screen mode, but then I don't think it's really the best application for testing with.