bpo-36670: fixed encoding issue with libregrtest on win systems by LorenzMende · Pull Request #15488 · python/cpython

If it's not too much work, could you create a PR with your alternative solution from bpo whereby you raise early and the load average calculation gets disabled.

This really feels like a lot of extra complexity for not much gain, the primary reason system load averages are reported in regrtest is to track down flaky parallel/race condition/non deterministic tests. Those are primarily run on CI machines and build-bots which are almost always English machines anyway