daisy_skate continues to build failed from 2138 ~ 2154 and the error message are all the same [1].

[1]
  TestLabException: Not enough DUTs for board: daisy_skate, pool: bvt; required: 4, found: 2
  Traceback (most recent call last):
    File "/usr/local/autotest/site_utils/run_suite.py", line 2030, in _run_task
      return _run_suite(options)
    File "/usr/local/autotest/site_utils/run_suite.py", line 1771, in _run_suite
      options.skip_duts_check)
    File "/usr/local/autotest/site_utils/diagnosis_utils.py", line 330, in check_dut_availability
      hosts=hosts)
  NotEnoughDutsError: Not enough DUTs for board: daisy_skate, pool: bvt; required: 4, found: 2