pythonLocation no longer being set in v4

[shadycuz]

Description:
When upgrading from setup-python@v3 to setup-python@v4, other jobs fail because env.pythonLocation is no longer being set.

Action version:
v4

Platform:

• Ubuntu
• macOS
• Windows

Runner type:

• Hosted
• Self-hosted

Tools version:
all?

Repro steps:
Here is the PR. Here is the failed build.

Expected behavior:
python location to be available.

Actual behavior:
It appears to be empty.

Here is the code that now fails with v4.

- name: Set up Python
   uses: actions/setup-python@v4

- name: Python Cache
   uses: actions/cache@v3
     with:
       path: ${{ env.pythonLocation }}
       key: ${{ env.pythonLocation }}-${{ hashFiles('tests/requirements.txt') }}

[MaksimZhukov]

Hello @shadycuz! Thank you for reporting this!
We will investigate the issue and let you know as soon as we have updates.

[dsame]

Hello @shadycuz
The problem appears because the step Set up Python does not have python version from the hosted toolcache.

You should point out some:

      - name: Set up Python
        uses: actions/setup-python@v4
        with:
          python-version: '3.9'

This build (with python-version:) shows the the pipeline fixed: https://github.com/akv-demo/setup-python-test/actions/runs/3495220045/jobs/5851739586#step:5:14

And this build (without python-version:) repros the issues: https://github.com/akv-demo/setup-python-test/actions/runs/3495204909/jobs/5851706555#step:5:16

Please confirm the answer solves the issue.

[shadycuz]

@dsame But I used to not have to manually specify python-version: '3.9' to get it to work. Was that a breaking change from v3 to v4.

Edit: your own experiment seems to show that it worked in v3 but doesn't in v4.

[dmitry-shibanov]

Hello @shadycuz. It is an expected behaviour because in v3 tag the action had default value for python-version input. It was removed in scope of this pull request.

[shadycuz]

Alright alright, I read throught the 4.0 release notes again and it does seem to call out that the default is going away. I think it could be clearer. Same with the error msg. If a user did not specify python-version and you don't find a python file. Then perhaps you could tell them they need one or the other.

I don't really like this change, but I guess its time I use the python version file.