[BUG] NanoVDB new device buffer segfault due to "cudaCpuDeviceId"

[ZephirFXEC]

Bug: Segfault in DeviceBuffer constructor

OpenVDB 12.1.0
Windows 10
Cuda 12.8

Summary:
Creating a nanovdb::GridHandle<nanovdb::cuda::DeviceBuffer> on the host and passing it to a cuda function such as nanovdb::tools::cuda::voxelsToGrid causes a segmentation fault. The crash occurs because the DeviceBuffer(const HostBuffer&, ...) constructor defaults its device parameter to cudaCpuDeviceId (-1), which is then used as an invalid index for the mGpuData array. Removing the "cudaCpuDeviceId" and setting it to 0 works.

Problematic Code :

openvdb/nanovdb/nanovdb/cuda/DeviceBuffer.h

Lines 130 to 142 in dd0ac13

	/// @brief Copy-constructor from a HostBuffer
	/// @param buffer host buffer from which to copy data
	/// @param device id of the device on which to initialize the buffer
	/// @param stream cuda stream
	DeviceBuffer(const HostBuffer& buffer, int device = cudaCpuDeviceId, cudaStream_t stream = 0)
	: DeviceBuffer(buffer.size(), device, stream)
	{
	if (mCpuData) {
	cudaCheck(cudaMemcpy(mCpuData, buffer.data(), mSize, cudaMemcpyHostToHost));
	} else if (mGpuData[device]) {
	cudaCheck(cudaMemcpyAsync(mGpuData[device], buffer.data(), mSize, cudaMemcpyHostToDevice, stream));
	}
	}

Reproduce :

Host Code :

	nanovdb::GridHandle<nanovdb::cuda::DeviceBuffer> handle;
	CreateIndexGrid(data, handle, voxelSize); // <- Function from .cu file 

Device Code :

void create_index_grid(HNS::GridIndexedData& data, nanovdb::GridHandle<nanovdb::cuda::DeviceBuffer>& handle, const float voxelSize) {
	nanovdb::Coord* d_coords = nullptr;
	cudaMalloc(&d_coords, data.size() * sizeof(nanovdb::Coord));
	cudaMemcpy(d_coords, data.pCoords(), data.size() * sizeof(nanovdb::Coord), cudaMemcpyHostToDevice);
	handle = nanovdb::tools::cuda::voxelsToGrid<nanovdb::ValueOnIndex, nanovdb::Coord*>(d_coords, data.size(), voxelSize);
	cudaFree(d_coords);
}

This is maybe not a bug rather an unexpected behaviour, as it was working fine before the DeviceBuffer rework in OpenVDB 12.0,