Comment 4 for bug 1672033

A little bit of debugging and investigating confirm what is in log above:

libmutter cannot get a monitor and crashes here:
https://github.com/GNOME/mutter/blob/master/src/backends/meta-backend.c#L128-L133

  primary =
    meta_monitor_manager_get_primary_logical_monitor (monitor_manager);

  meta_backend_warp_pointer (backend,
                             primary->rect.x + primary->rect.width / 2,
                             primary->rect.y + primary->rect.height / 2);

because 'primary' is not a valid pointer.

So,
1. This should be reported to gnome/mutter developers, so they check all their pointers and terminate in clean way with meta_fatal("failed to get primary monitor"); or something like that.
2. We have to understand, why libmutter fails to get primary logical monitor. Does Xorg need some permissions?