Error importing mne on Windows

Support & Discussions
1

I am to import mne-python using the github actions automatic testing, and get the following error when importing

  • MNE version: 1.3.0
  • operating system: Windows 10

using Windows only.

import mne

.tox\py310\lib\site-packages\mne_init_.py:130: in
set_log_level(None, False)
.tox\py310\lib\site-packages\mne\utils_logging.py:204: in set_log_level
verbose = get_config(‘MNE_LOGGING_LEVEL’, ‘INFO’)
.tox\py310\lib\site-packages\mne\utils\config.py:234: in get_config
config_path = get_config_path(home_dir=home_dir)
.tox\py310\lib\site-packages\mne\utils\config.py:184: in get_config_path
val = op.join(_get_extra_data_path(home_dir=home_dir),
.tox\py310\lib\site-packages\mne\utils\config.py:330: in _get_extra_data_path
if op.isdir(op.join(os.getenv(‘APPDATA’), ‘.mne’)):
C:\hostedtoolcache\windows\Python\3.10.9\x64\lib\ntpath.py:104: in join
path = os.fspath(path)
E TypeError: expected str, bytes or os.PathLike object, not NoneType

I do not get this error in Linux or Mac however. Maybe someone encountered something similar?

2

Looks like a bug to me. Apparently the APPDATA environment variable is not set and we don’t handle this case gracefully. As a workaround, can you try to set the variable to an arbitrary value?

Best wishes,
Richard

3

Thanks for the quick response!

Tbh I am not sure how I can change that, since I get this error from an automatic testing framework via tox with github workflows…

When I import mne on my local Windows machine it does not come up.

Also, I came across this commit some time ago implementing the check for APPDATA:

It might be that “USERPROFILE” instead of APPDATA would need to be checked?

For completeness here my github workflow .yml file:

name: Tests
on:
  push:
    branches:
      - main
      - '**'
    paths-ignore:
      - 'docs/**'
      - '*.md'
      - '*.rst'
      - '*.txt'
  pull_request:
    branches:
      - main
      - '*.x'
    paths-ignore:
      - 'docs/**'
      - '*.md'
      - '*.rst'
      - '*.txt'
jobs:
  tests:
    name: ${{ matrix.name }}
    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        include:
          - {name: 3.10 Windows, python: '3.10', os: windows-latest, tox: py310}
          - {name: 3.10 Mac, python: '3.10', os: macos-latest, tox: py310}
          - {name: 3.10 Linux, python: '3.10', os: ubuntu-latest, tox: py310}
          - {name: Lint, python: '3.10', os: ubuntu-latest, tox: lint}
          - {name: Typing, python: '3.10', os: ubuntu-latest, tox: typing}
          - {name: Style, python: '3.10', os: ubuntu-latest, tox: style}
    steps:
      - uses: actions/checkout@v3
      - uses: actions/setup-python@v4
        with:
          python-version: ${{ matrix.python }}
      - name: update pip
        run: |
          python -m pip install -U pip
      - name: get pip cache dir
        id: pip-cache
        run: echo "::set-output name=dir::$(pip cache dir)"
      - name: cache pip
        uses: actions/cache@v3
        with:
          path: ${{ steps.pip-cache.outputs.dir }}
          key: pip|${{ runner.os }}|${{ matrix.python }}|${{ hashFiles('requirements/*.txt') }}
          restore-keys: pip|${{ runner.os }}|${{ matrix.python }}
      - run: pip install tox
      - run: tox -e ${{ matrix.tox }}

with the corresponding tox.ini file:

[tox]
env_list =
   py3{10, 11}
 
skip_missing_interpreters = true
isolated_build = true


[testenv]
description = install pytest in a virtual environment and invoke it on the tests folder
deps =
    pytest>=7
    pytest-sugar
commands = pytest tests {posargs}
[tox]
env_list =
   py3{10, 11}
 
skip_missing_interpreters = true
isolated_build = true


[testenv]
description = install pytest in a virtual environment and invoke it on the tests folder
deps =
    pytest>=7
    pytest-sugar
commands = pytest tests {posargs}

I know its a super specific error, I checked on the github website Workflow syntax for GitHub Actions - GitHub Docs that their os is Windows Server 2022. So one option might be simple to not use the workflow on Windows, since MacOS and Linux are passing fine.

4

You can set environment variables in GH actions until we fix the bug:

5

Thanks again. Unfortunately though, the environment variable was not detected like that: Update tests.yml · neuromodulation/py_neuromodulation@6059a2c · GitHub

6

I started working on a fix: Fix configuration folder discovery on Windows by hoechenberger · Pull Request #11441 · mne-tools/mne-python · GitHub

Would you care to try this branch and see if it fixes your issue? You can install it via

pip install -U https://github.com/hoechenberger/mne-python/archive/refs/heads/config-dir-windows.zip