Can't Specify python-version-file as Absolute Path

[Kurt-von-Laven]

Description:
The python-version-file parameter currently only functions correctly with relative paths.

Action version:
v4.0.0

Platform:

• Ubuntu
• macOS
• Windows

Runner type:

• Hosted
• Self-hosted

Tools version:
All

Repro steps:
See ScribeMD/slack-templates@e653014 and its accompanying workflow run for a reproduction.

1. Create a composite action.

2. Create a .python-version file containing 3.10.4.

3. Call the setup-python action using an absolute path for the python-version-file:

   - name: Set up Python based on .python-version file.
     uses: actions/setup-python@v4.0.0
     with:
       python-version-file: "${{ github.action_path }}/.python-version"

Expected behavior:
I expected Python 3.10.4 to be set up.

Actual behavior:
The setup-python action crashes with:
Error: The specified python version file at: /home/runner/work/<action_name>/<action_name>/home/runner/work/<action_name>/<action_name>/.python-version does not exist

[vsafonkin]

Hi @Kurt-von-Laven we will take a look at this.

[vsafonkin]

@Kurt-von-Laven, as I see you have a typo:
"{{ github.action_path }}/.python-version" -> "${{ github.action_path }}/.python-version"

It works as expected:

- name: Set up Python based on .python-version file.
  uses: actions/setup-python@v4
  with:
    python-version-file: "${{ github.action_path }}/.python-version"

Successful run: https://github.com/vsafonkin/test-repo/runs/6858369737?check_suite_focus=true

[Kurt-von-Laven]

Thank you for pointing this out, but the typo was only in my filing of the issue, not the reproduction itself. The particular path I am using is only defined for composite actions, so maybe it’s the empty string otherwise?