skip tests on macos because multiprocess default switch to spawn since Python 3.8

[noklam]

Description

Fix #3702

Development notes

After long investigation, I found that the issue is closely related to #3704. This wasn't a problem because in older version, MacOS was default with "fork" process until Python 3.8.

This is not ideal as there are no way to run these tests locally as most core team member is using MacOS, alternative is debug this on GitPod as a temporary solution. However, there are no way to make these tests work unless there is a clever way to make mocking work with multi-process. I spend an hour trying and cannot find anything, so I stopped here until we prioritise this.

Tests passed as expected because I simply skip the test now.

Developer Certificate of Origin

We need all contributions to comply with the Developer Certificate of Origin (DCO). All commits must be signed off by including a Signed-off-by line in the commit message. See our wiki for guidance.

If your PR is blocked due to unsigned commits, then you must follow the instructions under "Rebase the branch" on the GitHub Checks page for your PR. This will retroactively add the sign-off to all unsigned commits and allow the DCO check to pass.

Checklist

• Read the contributing guidelines
• Signed off each commit with a Developer Certificate of Origin (DCO)
• Opened this PR as a 'Draft Pull Request' if it is work-in-progress
• Updated the documentation to reflect the code changes
• Added a description of this change in the RELEASE.md file
• Added tests to cover my changes
• Checked if this change will affect Kedro-Viz, and if so, communicated that with the Viz team

[ElenaKhaustova]

Tested on my side (MacOS):

• tests skipped as expected;
• one test is failing now: XFAIL tests/config/test_omegaconf_config.py::TestOmegaConfigLoader::test_overlapping_patterns - Logic failing but that's expected, right?

[noklam]

@ElenaKhaustova That's expected and not caused by this PR, I think @AhdraMeraliQB has a PR on it.

• Update broken OmegaConfigLoader test  #3696

tagging @merelcht to review this since we deal with the multiprocessing thing recently.

[merelcht]

🥲 So does this actually mean that the parallel runner is broken?

[noklam]

@merelcht not completely, at least pipeline are runnable, but it seems to break hooks at least (which is still quite bad).

I have open a draft PR to add some documentation about the use of configure_project originally, but I think we now need a ticket to look at this properly.

kedro-org/kedro-viz#1801

[ElenaKhaustova]

@ElenaKhaustova That's expected and not caused by this PR, I think @AhdraMeraliQB has a PR on it.

• Update broken OmegaConfigLoader test  #3696

tagging @merelcht to review this since we deal with the multiprocessing thing recently.

I do not think I had it before - just checked that it came with recent main updates, not the current one.

[noklam]

We had a discussion and it's properly best to start with fixing kedro-org/kedro-viz#1801. The problem is not Kedro specific, but rather "thread"/"process" safety in Python.

There are idea to provide some same hook class (or like AbstractDataset), it's unclear how it would look like so we will tackle the viz one as an example and see how it goes.

On the other hand, kedro run --runner ***** shows up on HEAP but the number is not significant, I dump a question in Slack to see if there are anyone using it, or is there a good reason not to use it.