The latest zako-release ran out of DUTs during the HWTest phase:

Triggered task: zako-release/R69-10869.0.0-bvt-arc
chromeos-golo-server1-253: 3ea75a8a91b59110 3
  Autotest instance created: cautotest-prod
  TestLabException: Not enough DUTs for board: zako, pool: bvt; required: 4, found: 3
  Traceback (most recent call last):
    File "/usr/local/autotest/site_utils/run_suite.py", line 1990, in _run_task
      return _run_suite(options)
    File "/usr/local/autotest/site_utils/run_suite.py", line 1726, 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: zako, pool: bvt; required: 4, found: 3

from https://luci-logdog.appspot.com/v/?s=chromeos/buildbucket/cr-buildbucket.appspot.com/8941214069119094208/+/steps/HWTest__bvt-arc_/0/stdout
on run https://cros-goldeneye.corp.google.com/chromeos/healthmonitoring/buildDetails?buildbucketId=8941214069119094208