// deterministic and because there is no real work anyway.
	par := cfg.BuildP
	if cfg.BuildN {
		par = 1
	}
	for i := 0; i < par; i++ {
		wg.Add(1)
		go func() {
			ctx := trace.StartGoroutine(ctx)
			defer wg.Done()
			for {
				select {
				case _, ok := <-b.readySema:
					if !ok {
						return
					}
					// Receiving a value from b.readySema entitles