Tooling Suggestion Checklist

• I have tried restarting my IDE and the issue persists.
• I have pulled the latest main branch of the repository.
• I have read and agree to Mocha's Code of Conduct and Contributing Guidelines
• I have searched for related issues and issues with the faq label, but none matched my issue.
• I want to provide a PR to resolve this

Overview

2025-08-17

• Run #4174: --exit tests occasionally fail (~2% chance), re-opened this one at medium priority
• Run #4201: --parallel test failing, increase timeout (2025-08-22), second instance total across thousands of runs of that test

Original overview:

The GitHub action to run all tests on various versions of Node and various operating systems has started returning intermittent test failures again.

• Passing run
• Failing run

The only difference (netlify.toml changed)