Perform check using implicit list length

[tomaarsen]

Resolves #34

Hello!

Pull request overview

• Perform compute capabilities check using implicit list length instead of ccs is not None, as ccs is always a list, so this if-statement is currently always True.

Details

The function within which the exception from #34 occurs:
https:/TimDettmers/bitsandbytes/blob/9b5f2eda8fbd3f042c4af7ed1b870525d4668f2a/bitsandbytes/cuda_setup/main.py#L99-L109
This function takes ccs from get_compute_capabilities:
https:/TimDettmers/bitsandbytes/blob/9b5f2eda8fbd3f042c4af7ed1b870525d4668f2a/bitsandbytes/cuda_setup/main.py#L65-L95

As you can see, ccs is initialized as a list, and is only optionally appended to. In short, it is never None, so ccs is not None is always True, even if ccs is an empty list.

I've resolved this by using the implicit list length check using if ccs:. The new traceback from the Colab provided by @justheuristic (Thank you for raising the issue, and providing the Colab) is:

Traceback

===================================BUG REPORT===================================
Welcome to bitsandbytes. For bug reports, please submit your error trace to: https://github.com/TimDettmers/bitsandbytes/issues
For effortless bug reporting copy-paste your error into this form: https://docs.google.com/forms/d/e/1FAIpQLScPB8emS3Thkp66nvqwmjTEgxp8Y9ufuWTzFyr9kJ5AoI47dQ/viewform?usp=sf_link
================================================================================
CUDA_SETUP: WARNING! libcudart.so not found in any environmental path. Searching /usr/local/cuda/lib64...
CUDA SETUP: CUDA runtime path found: /usr/local/cuda/lib64/libcudart.so
CUDA exception! Error code: no CUDA-capable device is detected
CUDA exception! Error code: initialization error
CUDA SETUP: Highest compute capability among GPUs detected: None
CUDA exception! Error code: no CUDA-capable device is detected
CUDA SETUP: CUDA version lower than 11 are currenlty not supported for LLM.int8(). You will be only to use 8-bit optimizers and quantization routines!!
CUDA SETUP: Detected CUDA version 00
CUDA SETUP: TODO: compile library for specific version: libbitsandbytes_cuda00_nocublaslt.so
CUDA SETUP: Defaulting to libbitsandbytes.so...
CUDA SETUP: CUDA detection failed. Either CUDA driver not installed, CUDA not installed, or you have multiple conflicting CUDA libraries!
CUDA SETUP: If you compiled from source, try again with `make CUDA_VERSION=DETECTED_CUDA_VERSION` for example, `make CUDA_VERSION=113`.

/usr/local/lib/python3.7/dist-packages/bitsandbytes/cuda_setup/paths.py:21: UserWarning: WARNING: The following directories listed in your path were found to be non-existent: {PosixPath('/usr/local/nvidia/lib64'), PosixPath('/usr/local/nvidia/lib')}
  "WARNING: The following directories listed in your path were found to "
/usr/local/lib/python3.7/dist-packages/bitsandbytes/cuda_setup/paths.py:99: UserWarning: /usr/local/nvidia/lib:/usr/local/nvidia/lib64 did not contain libcudart.so as expected! Searching further paths...
  f'{candidate_env_vars["LD_LIBRARY_PATH"]} did not contain '
/usr/local/lib/python3.7/dist-packages/bitsandbytes/cuda_setup/paths.py:21: UserWarning: WARNING: The following directories listed in your path were found to be non-existent: {PosixPath('"/usr/local/bin/dap_multiplexer","enableLsp"'), PosixPath('{"kernelManagerProxyPort"'), PosixPath('["--ip=172.28.0.2"],"debugAdapterMultiplexerPath"'), PosixPath('"172.28.0.3","jupyterArgs"'), PosixPath('true}'), PosixPath('6000,"kernelManagerProxyHost"')}
  "WARNING: The following directories listed in your path were found to "
/usr/local/lib/python3.7/dist-packages/bitsandbytes/cuda_setup/paths.py:21: UserWarning: WARNING: The following directories listed in your path were found to be non-existent: {PosixPath('/env/python')}
  "WARNING: The following directories listed in your path were found to "
/usr/local/lib/python3.7/dist-packages/bitsandbytes/cuda_setup/paths.py:21: UserWarning: WARNING: The following directories listed in your path were found to be non-existent: {PosixPath('module'), PosixPath('//ipykernel.pylab.backend_inline')}
  "WARNING: The following directories listed in your path were found to "

---------------------------------------------------------------------------

Exception                                 Traceback (most recent call last)

[<ipython-input-1-49909ea8fb42>](https://localhost:8080/#) in <module>
----> 1 import bitsandbytes

5 frames

[/usr/local/lib/python3.7/dist-packages/bitsandbytes/cextension.py](https://localhost:8080/#) in initialize(self)
     25                 print('CUDA SETUP: CUDA detection failed. Either CUDA driver not installed, CUDA not installed, or you have multiple conflicting CUDA libraries!')
     26                 print('CUDA SETUP: If you compiled from source, try again with `make CUDA_VERSION=DETECTED_CUDA_VERSION` for example, `make CUDA_VERSION=113`.')
---> 27                 raise Exception('CUDA SETUP: Setup Failed!')
     28             self.lib = ct.cdll.LoadLibrary(binary_path)
     29         else:

Exception: CUDA SETUP: Setup Failed!

I would argue that the new traceback is much clearer.

• Tom Aarsen

[TimDettmers]

Thank you!