whisperX/CUDNN_TROUBLESHOOTING.md

Troubleshooting cuDNN Loading Errors

This guide helps resolve common cuDNN-related errors when running WhisperX on GPU. These issues typically occur when the system can't locate cuDNN libraries or finds conflicting versions.

Unable to Load cuDNN Libraries

If you encounter the following error when running WhisperX:

Unable to load any of {libcudnn_cnn.so.9.1.0, libcudnn_cnn.so.9.1, libcudnn_cnn.so.9, libcudnn_cnn.so}

This means the cuDNN libraries are installed (via whisperx dependencies) but aren't in a location where the system's dynamic linker can find them.

Solution 1: Add to LD_LIBRARY_PATH (Recommended)

Add this at the start of your Python script or notebook:

import os

# Get current LD_LIBRARY_PATH
original = os.environ.get("LD_LIBRARY_PATH", "")

cudnn_path = "/usr/local/lib/python3.12/dist-packages/nvidia/cudnn/lib/"
os.environ['LD_LIBRARY_PATH'] = original + ":" + cudnn_path

Note: Adjust the Python version (python3.12) to match your environment.

Solution 2: Symlink to LD_LIBRARY_PATH Directory

If Solution 1 didn't work and you still get the "unable to load" error, symlink the libraries to a directory that's already in your LD_LIBRARY_PATH:

1. Check what's in your LD_LIBRARY_PATH: echo "$LD_LIBRARY_PATH"

2. Assuming that there is only one path set.
   Symlink the downloaded libcudnn files to that path:
   ln -s /usr/local/lib/python3.12/dist-packages/nvidia/cudnn/lib/libcudnn* "$LD_LIBRARY_PATH"/

   Note: If LD_LIBRARY_PATH contains multiple paths (separated by :), pick one directory and use it instead of "$LD_LIBRARY_PATH". For example: /usr/lib/x86_64-linux-gnu/

cuDNN Version Incompatibility

If you encounter this error:

RuntimeError: cuDNN version incompatibility: PyTorch was compiled against (9, 10, 2) but found runtime version (9, 2, 1)

This means PyTorch is finding a different cuDNN version than the one it was compiled with. PyTorch comes bundled with its own cuDNN, but a conflicting cuDNN in LD_LIBRARY_PATH is taking precedence.

Solution: Remove Conflicting cuDNN from Path

Check if there's a conflicting cuDNN path:

echo $LD_LIBRARY_PATH

If you see paths pointing to older cuDNN installations (e.g., system-installed cuDNN or manually downloaded), try one of these:

Option 1: Clear LD_LIBRARY_PATH temporarily

import os
# Let PyTorch use its bundled cuDNN
os.environ.pop('LD_LIBRARY_PATH', None)

Option 2: Set LD_LIBRARY_PATH to only the correct version

import os
# Point only to the cuDNN that matches PyTorch's compiled version
os.environ['LD_LIBRARY_PATH'] = "/usr/local/lib/python3.12/dist-packages/nvidia/cudnn/lib/"

Note: This error is unlikely on a clean install. If it occurs anyway, open an issue. If you've modified system libraries or CUDA/cuDNN, the options above should help resolve most cases.