pip installing PyYAML crashes the Action running

[jameshiebert]

Describe the bug
pip installing a version of PyYAML which is not the version being used to run the workflow causes the workflow runner to crash on subsequent steps.

2020-07-15T21:47:13.5356959Z FileNotFoundError: [Errno 2] No such file or directory: '/opt/hostedtoolcache/Python/3.7.8/x64/lib/python3.7/site-packages/PyYAML-5.3.1-py3.7-linux-x86_64.egg'
2020-07-15T21:47:13.5916339Z ##[error]Process completed with exit code 1.

Which version of the action are you using?

• v1
• v2
• Some other tag (such as v2.0.1 or master)

Environment

• self-hosted
• Linux
• Windows
• Mac

If applicable, please specify if you're using a container

Python Versions
3.7.8

To Reproduce
Steps to reproduce the behavior:

1. Run a workflow e.g. this one that pip installs some version of PyYAML
2. On my workflow, scroll down to "Install Conflicting PyYAML"
3. Notice the FileNotFoundError which is not from execution of my workflow.
4. Notice that the "Do Something Else" step is not run.

Run/Repo Url
https://github.com/jameshiebert/action/runs/875331441?check_suite_focus=true

Additional context
I guess the right (?) way to work around this is to install everything in a virtual environment (as shown in the following commit), but:

1. There's nothing in the README (that I can find, at least) that says this is necessary, and
2. I'd argue that it's a bug (or at the very least, not proper encapsulation) if the user is able to cause the workflow runner to crash.

If I'm doing something wrong, I'd be happy to hear about it :) Thanks.

[nathan-weinberg]

Experiencing the same issue here https://github.com/nathan-weinberg/jeeves/pull/133/checks?check_run_id=875661858

[Ivaylo-Bachvarov]

Seems like a bug for me. In the official documentation the action is used without virtualenv: https://docs.github.com/en/actions/language-and-framework-guides/using-python-with-github-actions

[nathan-weinberg]

I was able to workaround this by changing the pyyaml version from 5.1 to 5.3.1 in my requirements.txt

[maxim-lobanov]

Hello everyone, this issue is related to image, not the setup-python task. We are working on investigation and fix. Progress can be tracked in actions/runner-images#1202 (comment)

[Borda]

@nathan-weinberg I have tried to force pyyaml==5.3.1 before installing requirements.txt but it did not help...

[nathan-weinberg]

@Borda Here is the PR in which I made the change - https://github.com/nathan-weinberg/jeeves/pull/135/files

You may need to change the action version to v2

[nikita-bykov]

Hello @jameshiebert!
The related issue from virtual-environments was resolved. I just tested it and everything works as expected for me. Could you please confirm that it works for you too?

[nikita-bykov]

@jameshiebert I'm going to close the issue, but feel free to contact us if you have any questions.