cmux test bisect PR CI runs selected tests, so a package suite can stay red on main for weeks with nobody noticing. This skill finds the commit behind each failure on CI, never on the Mac (no full cmux builds on laptops). App-host ( ) failures on main have their own automatic bisect (#14510). Use this skill for the SwiftPM package suites under and that can run ( , , , , , ). Before you start 1. Get today's failing set from the red run: , then grep . Run the full suite twice if you have not already. A test that appears in only one run is a flake candidate, not a regression. 2. Search for an ex…