Function run_pb2 

pub fn run_pb2(
    problem: &ScheduleProblem,
    pb2: &Pb2,
    budget: u64,
    seed: u64,
) -> Result<PbtReport>

Runs single-worker PB2 over problem for budget trials and assembles the same PbtReport the PBT driver does.

Each trial trains one segment from its parent’s carried checkpoint and records its own, so PB2’s GP-UCB exploit copies real checkpoint references through the real loop, exactly as the PBT driver does — the only difference between the two runs is the scheduler.

Errors

Anything the study loop, storage or the objective reports.