Editing Toolkit CI: Run phpunit tests fails

[jeyip]

Steps to reproduce

1. Modify code in the wp-calypso/apps/editing-toolkit directory (I commented out lines 19 and 20 in wp-calypso/apps/editing-toolkit/editing-toolkit-plugin/dotcom-fse/blocks/post-content/edit.js
2. Create a test branch and push the changes to Github
3. Verify that the Github CI Job for Run phpunit tests fails

What I expected

The php unit tests CI job for the editing toolkit should pass without issue when I haven't made modifications to PHP files.

What happened instead

The CI job failed for unrelated configuration issues with nodegit

Screenshot / Video

Source: https://github.com/Automattic/wp-calypso/runs/1376351946?check_suite_focus=true

Context / Source

p1604956506439800-slack-C02DQP0FP

Potential Causes

"node-git was recently updated in the wp-env package in Gutenberg, but I doubt that has made it to npm yet. Maybe that patch in Gutenberg is meant to fix this issue: WordPress/gutenberg#26712"

[jeyip]

I've confirmed this bug and am assigning a priority of normal. I didn't assign a low priority because, although this isn't causing any user facing issues, the longer automated tests continue to fail, the less credibility they hold for other developers. Given enough time, other devs become more inclined to ignore some of these automated checks altogether, causing actual regressions to be ignored as well.

We should fix this within a reasonable amount of time.