Also replace root version to Python3

Philip Kahn

2018-05-04 3459c47bfa02d23d300df9a44ba3ec9c958850fe

 src/cuda.c

@@ -177,4 +177,7 @@
   cudaStreamSynchronize(get_cuda_stream());
}

#endif
#else // GPU
#include "cuda.h"
void cuda_set_device(int n) {}
#endif // GPU