With the latest version 5.2.0, if VirtualBox is started with a non-local DISPLAY, it dumps core. [0]% _IceTransSocketUNIXConnect: Cannot connect to non-local host mizar.xyzzy Qt WARNING: Qt: Session management error: Could not open network socket libGL error: No matching fbConfigs or visuals found libGL error: failed to load driver: swrast [1] + segmentation fault VirtualBox [0]% This worked (apart from a few glitches) with 5.1.30. Both local and remote hosts FreeBSD 11.1.
works again, most likely due to a recent qt update