It seems that HDK's BV_KDOPTree/GU_KDOPTree cannot handle the polygons with the same barycenter and cause a segmentation fault. The problem is less esoteric than it might seem - I am experimenting with a BVH construction for a game collision geometry and polygons that differ only in vertex order are a necessity. Also the polygons doesn't have to be co-planar to crash Houdini - a same barycenter that is the fault condition.
I am attaching a test plug-in source and a test scene. I don't have access to Houdini 12 beta, so would be great if somebody could try it out with H12 to check whether the problem persists.
My guess is there is a bug in BV_KDOPTree implementation, but I might miss a point with something, in this case please advise me.