text: Title: I have meet an unknown error when I try the mnist nas example.
  Body: **Describe the issue**:
  
  [2022-04-13 19:34:12] INFO (nni.experiment/MainThread) Creating experiment, Experiment ID: cau4bj2g
  [2022-04-13 19:34:12] INFO (nni.experiment/MainThread) Connecting IPC pipe...
  [2022-04-13 19:34:13] INFO (nni.experiment/MainThread) Starting web server...
  [2022-04-13 19:34:15] INFO (nni.experiment/MainThread) Setting up...
  [2022-04-13 19:34:17] INFO (nni.runtime.msg_dispatcher_base/Thread-3) Dispatcher started
  [2022-04-13 19:34:17] INFO (nni.retiarii.experiment.pytorch/MainThread) Web UI URLs: http://169.254.240.252:8081 http://169.254.175.234:8081 http://169.254.108.7:8081 http://169.254.237.19:8081 http://192.168.195.1:8081 http://192.168.75.1:8081 http://192.168.160.7:8081 http://169.254.27.48:8081 http://127.0.0.1:8081
  [2022-04-13 19:34:17] INFO (nni.retiarii.experiment.pytorch/MainThread) Start strategy...
  [2022-04-13 19:34:21] INFO (root/MainThread) Successfully update searchSpace.
  [2022-04-13 19:34:21] INFO (nni.retiarii.strategy.bruteforce/MainThread) Random search running in fixed size mode. Dedup: on.
  Exception in thread Thread-3:
  Traceback (most recent call last):
    File "D:\anaconda_home\envs\nni_test\lib\threading.py", line 916, in _bootstrap_inner
      self.run()
    File "D:\anaconda_home\envs\nni_test\lib\threading.py", line 864, in run
      self._target(*self._args, **self._kwargs)
    File "D:\anaconda_home\envs\nni_test\lib\site-packages\nni\runtime\msg_dispatcher_base.py", line 51, in run
      command, data = receive()
    File "D:\anaconda_home\envs\nni_test\lib\site-packages\nni\runtime\protocol.py", line 61, in receive
      header = _in_file.read(16)
  OSError: [Errno 22] Invalid argument
  
  
  **Environment**:
  - NNI version: 2.6.1
  - Training service (local|remote|pai|aml|etc): local
  - Client OS:windows
  - Server OS (for remote mode only):
  - Python version:3.6
  - PyTorch/TensorFlow version:1.10
  - Is conda/virtualenv/venv used?:is
  - Is running in Docker?:
  
  **<html>
  <body>
  
  
  absl-py | 1.0.0 |  
  -- | -- | --
  bzip2 | 1.0.8 |  
  ca-certificates | 2021.10.8 |  
  cachetools | 4.2.4 |  
  certifi | 2021.10.8 |  
  charset-normalizer | 2.0.12 |  
  cloudpickle | 2.0.0 |  
  colorama | 0.4.4 |  
  contextlib2 | 21.6.0 |  
  cudatoolkit | 9.2.148 |  
  dill | 0.3.4 |  
  filelock | 3.3.2 |  
  google-auth | 2.6.2 |  
  google-auth-oauthlib | 0.4.6 |  
  grpcio | 1.45.0 |  
  idna | 3.3 |  
  importlib-resources | 5.4.0 |  
  json-tricks | 3.15.5 |  
  libffi | 3.4.2 |  
  libzlib | 1.2.11 |  
  markdown | 3.3.6 |  
  networkx | 2.5.1 |  
  nni | 2.6.1 |  
  numpy | 1.19.3 |  
  oauthlib | 3.2.0 |  
  openssl | 3.0.2 |  
  pandas | 1.1.5 |  
  pillow | 8.4.0 |  
  pip | 21.3.1 |  
  protobuf | 3.19.4 |  
  pyasn1 | 0.4.8 |  
  pyasn1-modules | 0.2.8 |  
  python | 3.6.15 |  
  python-dateutil | 2.8.2 |  
  pytz | 2022.1 |  
  requests | 2.27.1 |  
  requests-oauthlib | 1.3.1 |  
  rsa | 4.8 |  
  schema | 0.7.5 |  
  scipy | 1.5.4 |  
  setuptools | 59.6.0 |  
  six | 1.16.0 |  
  sqlite | 3.38.2 |  
  tensorboard | 2.8.0 |  
  tensorboard-data-server | 0.6.1 |  
  tensorboard-plugin-wit | 1.8.1 |  
  thop | 0.0.31-2005241907 |  
  tk | 8.6.12 |  
  torch | 1.10.0+cpu |  
  torchaudio | 0.10.0+cu113 |  
  torchvision | 0.11.0+cpu |  
  tqdm | 4.63.0 |  
  typeguard | 2.13.3 |  
  typing-extensions | 4.1.1 |  
  ucrt | 10.0.20348.0 |  
  urllib3 | 1.26.9 |  
  vc | 14.2 |  
  vs2015_runtime | 14.29.30037 |  
  wcwidth | 0.2.5 |  
  werkzeug | 2.0.3 |  
  wheel | 0.37.1 |  
  xz | 5.2.5 |  
  zipp | 3.6.0 |  
  
  
  </body>
  </html>**
  **Configuration**:
   - Experiment config (remember to remove secrets!):
   - Search space:
  
  
  **Log message**:
   - nnimanager.log:
  [2022-04-13 20:17:33] INFO (NNIManager) Trial job x70fi status changed from WAITING to RUNNING
  [2022-04-13 20:17:41] INFO (NNIManager) Trial job x70fi status changed from RUNNING to FAILED
  
   - dispatcher.log:
   [2022-04-13 20:16:58] INFO (nni.experiment/MainThread) Creating experiment, Experiment ID: [36mbntk1sfo[0m
  [2022-04-13 20:16:58] INFO (nni.experiment/MainThread) Connecting IPC pipe...
  [2022-04-13 20:17:00] INFO (nni.experiment/MainThread) Starting web server...
  [2022-04-13 20:17:02] INFO (nni.experiment/MainThread) Setting up...
  [2022-04-13 20:17:04] INFO (nni.runtime.msg_dispatcher_base/Thread-3) Dispatcher started
  [2022-04-13 20:17:04] INFO (nni.retiarii.experiment.pytorch/MainThread) Web UI URLs: [36mhttp://169.254.240.252:8081 http://169.254.175.234:8081 http://169.254.108.7:8081 http://169.254.237.19:8081 http://192.168.195.1:8081 http://192.168.75.1:8081 http://192.168.160.7:8081 http://169.254.27.48:8081 http://127.0.0.1:8081[0m
  [2022-04-13 20:17:04] INFO (nni.retiarii.experiment.pytorch/MainThread) Start strategy...
  [2022-04-13 20:17:08] INFO (root/MainThread) Successfully update searchSpace.
  [2022-04-13 20:17:08] INFO (nni.retiarii.strategy.bruteforce/MainThread) Random search running in fixed size mode. Dedup: on.
  
   - nnictl stdout and stderr:
   stdout:
  ERROR: C:\Users\suntao\nni-experiments\bntk1sfo\log\nnictl_stdout.log does not exist!
  stderr:
  ERROR: C:\Users\suntao\nni-experiments\bntk1sfo\log\nnictl_stderr.log does not exist!
  
  <!--
  Where can you find the log files:
  LOG: https://github.com/microsoft/nni/blob/master/docs/en_US/Tutorial/HowToDebug.md#experiment-root-director
  STDOUT/STDERR: https://github.com/microsoft/nni/blob/master/docs/en_US/Tutorial/Nnictl.md#nnictl%20log%20stdout
  -->
  
  
  **How to reproduce it?**: