Why does Chroma.from_documents throw an access violation (0xC0000005) after reinstalling dependencies?

Below is a summary of a possible path to troubleshoot and resolve this access violation error (0xC0000005) that occurs when calling Chroma.from_documents in your code:

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1. Check Underlying Dependencies

An access violation can occur when a compiled dependency (for instance hnswlib) is built against a different CPU architecture or mismatched runtime. Even if everything was working before, reinstalling from a fresh repo may have introduced a subtle change in the versions. Try the following:

• Reinstall/Rebuild hnswlib:
  Ensure you’re getting an appropriate binary wheel for your Windows setup. If you see similar “clang” or build errors in logs (even if warnings), reinstall hnswlib:

  BASHCopied
  pip uninstall hnswlib
  pip install hnswlib

• Verify other dependencies:
  Double-check that your versions of chromadb, transformers, and any other compiled dependency match those known to work with your code.

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2. Investigate the Embedding Model Loading

Since the error occurs during the call to Chroma.from_documents—when it attempts to load the FastEmbedEmbeddings model ("BAAI/bge-small-en")—it’s possible there’s an issue with how the model is cached or loaded.

• Test the Embedding Separately:
  Isolate the embedding load before passing it to Chroma. For example:

  PYTHONCopied
  from your_embedding_module import FastEmbedEmbeddings
  
  cache_dir = "local_cache"
  embedder = FastEmbedEmbeddings(model_name="BAAI/bge-small-en", cache_dir=cache_dir)
  # Try a dummy encode call to verify that it works.
  dummy_embedding = embedder.embed("Test text.")
  print(dummy_embedding)

  This can help determine if the error is with the embedder or when Chroma uses it.

• Clear or Update the Cache:
  Sometimes a corrupted model file or cache can lead to crashes. Try manually deleting the local cache directory (or renaming it) and then running your code so the model re-downloads.

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3. Windows-Specific Considerations

The warning about symlink support on Windows might not be directly related to the access violation—but it hints that your environment may need some tweaks:

• Developer Mode / Administrator:
  You already activated Developer Mode. Alternatively, try running your Python process as administrator to see if that helps.

• Disable Symlink Warning (Optional):
  Set the environment variable to disable the symlink warning if you’re concerned it may affect behavior (though it normally only affects disk space):

  BASHCopied
  set HF_HUB_DISABLE_SYMLINKS_WARNING=1

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4. Virtual Environment Consistency

Since you mentioned the code was working before and now isn’t, consider:

• Recreating your Virtual Environment:
  Sometimes leftovers or mismatched binaries in your environment can cause issues. Create a fresh virtual environment and reinstall only the necessary packages.

  BASHCopied
  python -m venv new_env
  new_env\Scripts\activate   # On Windows
  pip install -r requirements.txt

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Conclusion

Start by isolating whether the crash happens when loading the FastEmbedEmbeddings model or when calling Chroma.from_documents. Reinstall key dependencies (like hnswlib) and ensure that your cached files aren’t corrupted. Also, ensure that all binaries are built for your specific CPU architecture (especially on Windows). These steps have helped others troubleshoot exit code 0xC0000005 in similar contexts.

Let me know if these suggestions help or if there is more information you uncover during testing!