Inconsistent Python version between steps with macos-latest

[jtpio]

Description:

A couple of days ago some CI checks that run on macos-latest with older versions of Python (3.7, 3.8, 3.9) started failing.

Action version:

actions/setup-python@v4

Platform:

• Ubuntu
• macOS
• Windows

Runner type:

• Hosted
• Self-hosted

Tools version:

- name: Install Python
  uses: actions/setup-python@v4
  with:
    python-version: '3.7'
    architecture: 'x64'

Repro steps:

Here is a public example: https://github.com/jupyter/notebook/runs/7973591481

There is also this issue with screenshots comparing macos to linux: jupyterlab/jupyterlab#12991

Expected behavior:

pip should correspond to the Python setup with actions/setup-python (in the example above), when invoked with python -m pip or python3 -m pip.

Actual behavior:

In https://github.com/jupyter/notebook/runs/7973591481 we notice a Python version mismatch:

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Thanks for your help!

[dmitry-shibanov]

Hello @jtpio. Thank you for your report. I think the issue comes through the specifying the default shell. It prepends extra paths that is why it resolves system python firstly. Could you please get rid of bash -l for python/pip steps ?

[jtpio]

Oh nice, many thanks @dmitry-shibanov for the hint 👍

We still need bash on windows to be able to use wildcards in file names. But it seems switching from bash -l {0} to bash -e {0} does the trick.

Linking to this PR where this was investigated, in case other folks experience something similar: jupyter/notebook#6523

Thanks!