Unable to import faiss

Beginners
1

Hello,

I am running Transformers on a Mac OS with Python 3.8 in a virtual environment.

I have faiss-cpu 1.7.0 installed in the env.

(venv) sergey_mkrtchyan transformers (master) $ python
Python 3.8.6 (v3.8.6:db455296be, Sep 23 2020, 13:31:39)
[Clang 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>>
>>> import faiss
>>> faiss.__version__
'1.7.0'

However transformers repo is doing an additional check of the version of the package using importlib_metadata in transformers/src/file_utils.py which ends up failing on me with “RagRetriever requires the faiss library but it was not found in your environment.”

_faiss_available = importlib.util.find_spec("faiss") is not None
try:
    _faiss_version = importlib_metadata.version("faiss")
    logger.debug(f"Successfully imported faiss version {_faiss_version}")
except importlib_metadata.PackageNotFoundError:
    _faiss_available = False

This is where it fails, mind you _faiss_available = importlib.util.find_spec("faiss") line above works just fine, but fails on the _faiss_version = importlib_metadata.version("faiss") line unable to find the faiss package.

Not sure if it’s an issue in the repo or something wrong on my side. Any experience with this?

Thank you!

1 Like
2

I am facing the same issue. No version of the faiss library is being recognized as present in the environment I am running (installed through conda). I did solve this problem before, but I remember it being a pain; I built the library from source but had to deal with many issues along the way.

Edit:
I was just able to get it to be recognised.

Solution:

if you are able to import the library ( from terminal start python):
python
import faiss
print(faiss)

/home/akinwilson/miniconda3/envs/envRag/lib/python3.7/site-packages/faiss/init.py

take the path;
/home/akinwilson/miniconda3/envs/envRag/lib/python3.7/site-packages/faiss

then in your bashrc file:
nano ~/.bashrc
add this line to the end of the file:
export PYTHONPATH=$HOME/miniconda3/lib/python3.8/site-packages/faiss
Note that I have changed the home directory to a variable.
save it.

Then finally, set the bashrc file as source again to reload the paths;
source ~/.bashrc

Restart any virtual environment and everything should work fine.

3

Thanks, just to let you know, this has been fixed on the master branch now.

_faiss_available = importlib.util.find_spec("faiss") is not None
try:
    _faiss_version = importlib_metadata.version("faiss")
    logger.debug(f"Successfully imported faiss version {_faiss_version}")
except importlib_metadata.PackageNotFoundError:
    try:
        _faiss_version = importlib_metadata.version("faiss-cpu")
        logger.debug(f"Successfully imported faiss version {_faiss_version}")
    except importlib_metadata.PackageNotFoundError:
        _faiss_available = False
4

This issue still persists (if you have faiss-gpu installed)
I think it should be updated as:

# We need to check all three `faiss` and `faiss-cpu` and `faiss-gpu`
try:
    _faiss_version = importlib.metadata.version("faiss")
    logger.debug(f"Successfully imported faiss version {_faiss_version}")
except importlib.metadata.PackageNotFoundError:
    try:
        _faiss_version = importlib.metadata.version("faiss-cpu")
        logger.debug(f"Successfully imported faiss version {_faiss_version}")
    except importlib.metadata.PackageNotFoundError:
        try:
            _faiss_version = importlib.metadata.version("faiss-gpu")
            logger.debug(f"Successfully imported faiss version {_faiss_version}")
        except importlib.metadata.PackageNotFoundError:
            _faiss_available = False
5

Would be great to open a PR :slight_smile: