Error when cudart found, but cuda not #81
Description
#16 1.968 ===================================BUG REPORT===================================
#16 1.968 Welcome to bitsandbytes. For bug reports, please submit your error trace to: https://github.com/TimDettmers/bitsandbytes/issues
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#16 1.968 ================================================================================
#16 1.968 CUDA_SETUP: WARNING! libcudart.so not found in any environmental path. Searching /usr/local/cuda/lib64...
#16 1.968 CUDA SETUP: CUDA runtime path found: /usr/local/cuda/lib64/libcudart.so
#16 1.968 CUDA SETUP: WARNING! libcuda.so not found! Do you have a CUDA driver installed? If you are on a cluster, make sure you are on a CUDA machine!
#16 1.968 from .autograd._functions import (
#16 1.968 /opt/conda/lib/python3.10/site-packages/bitsandbytes/autograd/_functions.py:5: in
#16 1.968 import bitsandbytes.functional as F
#16 1.968 /opt/conda/lib/python3.10/site-packages/bitsandbytes/functional.py:13: in
#16 1.968 from .cextension import COMPILED_WITH_CUDA, lib
#16 1.968 /opt/conda/lib/python3.10/site-packages/bitsandbytes/cextension.py:41: in
#16 1.968 lib = CUDALibrary_Singleton.get_instance().lib
#16 1.968 /opt/conda/lib/python3.10/site-packages/bitsandbytes/cextension.py:37: in get_instance
#16 1.968 cls._instance.initialize()
#16 1.968 /opt/conda/lib/python3.10/site-packages/bitsandbytes/cextension.py:15: in initialize
#16 1.968 binary_name = evaluate_cuda_setup()
#16 1.968 /opt/conda/lib/python3.10/site-packages/bitsandbytes/cuda_setup/main.py:132: in evaluate_cuda_setup
#16 1.968 cc = get_compute_capability(cuda)
#16 1.968 /opt/conda/lib/python3.10/site-packages/bitsandbytes/cuda_setup/main.py:105: in get_compute_capability
#16 1.968 ccs = get_compute_capabilities(cuda)
#16 1.968 /opt/conda/lib/python3.10/site-packages/bitsandbytes/cuda_setup/main.py:83: in get_compute_capabilities
#16 1.968 check_cuda_result(cuda, cuda.cuDeviceGetCount(ctypes.byref(nGpus)))
#16 1.968 E AttributeError: 'NoneType' object has no attribute 'cuDeviceGetCount'
#16 ERROR: process "/bin/sh -c PYTHONPATH=. pytest tests/ --durations=0 --durations-min=1.0 -v" did not complete successfully: exit code: 4