if _, ok := err.(BucketExists); !ok {
					t.Logf("unexpected error: %T: %v", err, err)
					return
				}
				mu.Lock()
				errs++
				mu.Unlock()
				return
			}
			mu.Lock()
			ok++
			mu.Unlock()
		}()
	}
	close(start)
	wg.Wait()
	if ok != 1 {
		t.Fatalf("want 1 ok, got %d", ok)
	}
	if errs != n-1 {