A workaround is to disable 3d acceleration in the guest settings. Then I get this warning instead of a crash:
OpenGL Warning: Failed to connect to host. Make sure 3D acceleration is enabled for this VM. And clutter applications run slowly rather than not at all. Seems rather obvious now, with hindsight! :) -- Sam Morris https://robots.org.uk/ PGP key id 1024D/5EA01078 3412 EA18 1277 354B 991B C869 B219 7FDB 5EA0 1078
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