I just tried it again with current git (Mesa 11.2.0-devel (git-040e314)). It works for me with with low settings. I played a few turns - it seems to be fine, albeit a bit slow. When using medium settings, the game hits the assert: CivBE: ../nptl/pthread_mutex_lock.c:353: __pthread_mutex_lock_full: Assertion `(-(e)) != 3 || !robust' failed. and doesn't start. But there is no system crash.