x = bvhtree.BVHTree.FromObject(C.active_object, C.scene)
Is broken in blender 2.8 builds for some time now. I also tested on latest build from 4 December.
Error message:
raceback (most recent call last):
File "<blender_console>", line 1, in <module>
SystemError: <built-in method FromObject of type object at 0x0444CA30> returned NULL without setting an error
