'cub is ambiguous' with 11.6 sdk and VS2022

Accelerated Computing CUDA CUDA NVCC Compiler
#1

I’m trying to compile code that worked fine in the past with VS2019 and 11.5 and earlier Cuda SDK’s. But now with VS2022 and 11.6. And I am getting errors where I seem to mix cub and thrust:

C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v11.6\include\cub\warp\specializations/warp_scan_shfl.cuh(121): error : “cub” is ambiguous
1> detected during:
1> instantiation of class “cub::WarpScanShfl<T, LOGICAL_WARP_THREADS, PTX_ARCH> [with T=int, LOGICAL_WARP_THREADS=32, PTX_ARCH=520]”
1>C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v11.6\include\cub\block\specializations…/…/warp/warp_scan.cuh(167): here
1> instantiation of class “cub::WarpScan<T, LOGICAL_WARP_THREADS, PTX_ARCH> [with T=int, LOGICAL_WARP_THREADS=32, PTX_ARCH=520]”
1>C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v11.6\include\cub\block\specializations/block_scan_warp_scans.cuh(81): here
1> instantiation of class “cub::BlockScanWarpScans<T, BLOCK_DIM_X, BLOCK_DIM_Y, BLOCK_DIM_Z, PTX_ARCH>::_TempStorage [with T=int, BLOCK_DIM_X=128, BLOCK_DIM_Y=1, BLOCK_DIM_Z=1, PTX_ARCH=520]”
1>C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v11.6\include\cub\util_type.cuh(369): here
1> instantiation of class “cub::AlignBytes::Pad [with T=cub::BlockScanWarpScans<int, 128, 1, 1, 520>::_TempStorage]”
1>C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v11.6\include\cub\util_type.cuh(376): here
1> instantiation of class “cub::AlignBytes [with T=cub::BlockScanWarpScans<int, 128, 1, 1, 520>::_TempStorage]”
1>C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v11.6\include\cub\util_type.cuh(428): here
1> [ 16 instantiation contexts not shown ]

#2

Ok I have found out why. The thrust library is now bringing the cub namespace into itself as thrust::cub. So now any code that was doing a ‘using namespace thrust’ in its .cu file and directly including the cub header gets this annoying error.