faiss installation issues in conda env

[felixsh]

I'm trying to install OpenOOD in a conda environment per yaml file, like so:

name: env
channels:
  - pytorch
  - nvidia
  - defaults
dependencies:
  - python=3.12
  - numpy
  - matplotlib
  - scikit-learn
  - scipy
  - tqdm
  - pytorch:pytorch
  - pytorch:torchvision
  - nvidia:pytorch-cuda=12.1
  - pytorch::faiss-gpu
  - cython
  - pip
  - pip:
    - git+https://github.com/Jingkang50/OpenOOD

Building with conda env create --file=env.yaml throws an error saying faiss-gpu>=1.7.2 can not be satisfied. Changing this to faiss>=1.7.2 in setup.py resolves the issue.

The problem is probably somewhere between pip and conda. On inspection conda list | grep faiss --> faiss-gpu, but pip list | grep faiss --> faiss and pip can not find the faiss-gpu package.

Not sure if this needs fixing or is a packaging issue with conda, either way the trinity of faiss, faiss-cpu, faiss-gpu is confusing. Maybe this helps somebody else trying to install OpenOOD in a conda env.

[zjysteven]

Thanks for sharing this. Just curious, what about removing pytorch::faiss-gpu in conda dependencies and just let pip alone to handle faiss installation?

[felixsh]

Letting pip handle the dependencies results in an error:

ERROR: Could not find a version that satisfies the requirement faiss-gpu>=1.7.2 (from openood) (from versions: none)
ERROR: No matching distribution found for faiss-gpu>=1.7.2

Installing with pip in python3.11 (no conda) produces a similar error. I guess the installation via pip is not intended, to quote the faiss-installation guide: "The supported way to install Faiss is through conda."

[zjysteven]

Right, turned out that the pypi package expects python >=3.7, <3.11. With as late as python 3.10 the pip installation still works but not with 3.11.

[felixsh]

Thanks for the clarification! So, I just missed the correct version.

I will stick with python 3.12 and the solution above for now, that seems to work just fine. From my side this can be closed, only suggestion I have to maybe add this as a note under the installation section.