Function train_report 

pub fn train_report(verdict: &Verdict) -> TrainReport

Reads a train’s verdict as the report its PRs get (D18, D49).

The four cases collapse to three states, and which two share one is the whole point. failure blames the change, and only Verdict::Failed may: an outage or a deadline posts error, because telling an author their work is red when our provider fell over is the confusion the seam exists to end. green is true for exactly one case, so a train never lands on a verdict that merely failed to say no.