I spent an embarrassingly long amount of time banging my head against a wall, and the issue ended up being shared_context not getting properly passed in an eglCreateContext call. I couldn't figure out why the OpenGL state is different at two calls which really ought to have had the same state, and as far as I could see the state was the same. If apitrace currently doesn't indicate this at all, it probably should (I guess I'd be willing to try and implement that if nobody else has time to do it, depending on how deep of an understanding of the codebase is necessary), or if it does indicate this in some way that I missed, it should probably be more prominent (maybe even color coding each call in some way, so it's easy to see at glance which calls belong together)