I assumed it was a log with level :warn sneaking in somewhere but no, the problem is different. I am still trying to pinpoint what’s going on, but the issue disappears completely with --max-cases=1, and then gradually starts to show up as I increase the concurrency of tests. At --max-cases=6 it’s almost always guaranteed to happen in my test suite.
Edit: I opened a bug report here: ExUnit.CaptureLog fails in tests on high concurrency · Issue #12692 · elixir-lang/elixir · GitHub we can move conversation there
