ImportError: cannot import name 'packaging' from 'pkg_resources' when trying to install causal_conv1d

I was trying to install "causal_conv1d" using:

pip install --no-cache-dir  -t /scratch/ahmed/lib  causal_conv1d==1.0.0

The error I got is:

Collecting causal_conv1d==1.0.0
  Downloading causal_conv1d-1.0.0.tar.gz (6.4 kB)
  Preparing metadata (setup.py) ... error
  error: subprocess-exited-with-error
  
  × python setup.py egg_info did not run successfully.
  │ exit code: 1
  ╰─> [9 lines of output]
      Traceback (most recent call last):
        File "<string>", line 2, in <module>
        File "<pip-setuptools-caller>", line 34, in <module>
        File "/tmp/pip-install-9i0wsv2k/causal-conv1d_fc0a21267f664102adca1aa336c93106/setup.py", line 19, in <module>
          from torch.utils.cpp_extension import (
        File "/scratch/ahmed/lib/torch/utils/cpp_extension.py", line 28, in <module>
          from pkg_resources import packaging  # type: ignore[attr-defined]
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      ImportError: cannot import name 'packaging' from 'pkg_resources' (/scratch/ahmed/lib/pkg_resources/__init__.py)
      [end of output]
  
  note: This error originates from a subprocess, and is likely not a problem with pip.
error: metadata-generation-failed

× Encountered error while generating package metadata.
╰─> See above for output.

note: This is an issue with the package mentioned above, not pip.
hint: See above for details.

Solution

I don't know the exact problem, but it seems this problem happened when I used two directories for Python "lib": one was the default Anaconda lib, and I had another separate one. The problem disappeared when I used only the default Anaconda lib. It works fine now.