codecov/project CI check fails but seems to require additional coverage on code unrelated to the PR

[leehart]

I think it's happened a few times where a PR has been submitted but the CI checks for code coverage appears to fail on unrelated code, or the only way to satisfy the requirement is to add more test coverage to code not related to the PR. Or perhaps there's some other requirement that isn't clear?

I'm not sure if this is an issue with the way the CI is configured or a problem associated with the coverage tests themselves, but it always seems unfair and inappropriate to require additional code coverage tests to be added to parts of the codebase that are not related to the original PR.

It causes PRs to get stuck in limbo, despite having passed all other reasonable requirements, e.g. #540

[alimanfoo]

I think codecov is using the wrong base. This possibly relevant: https://community.codecov.com/t/set-base-commit/1014/4