auto-sklearn: _pickle.UnpicklingError: pickle data was truncated

Describe the bug

I was running autosklearn for a hour on the dataframe kin8nm with id: 189 downloaded from OpenML and then autosklearn stops with this exception _pickle.UnpicklingError: pickle data was truncated

To Reproduce

Steps to reproduce the behavior:

1. Download the dataframe 189 with the OpenML API
2. Apply train_test_split
3. Create the automl instance:

automl = autosklearn.regression.AutoSklearnRegressor(
          time_left_for_this_task=timelife*60,
          per_run_time_limit=30,
          memory_limit=psutil.virtual_memory().available,
          n_jobs=-1,
          resampling_strategy_arguments = {'cv': 10}
)

Timelife in this case i-s equal to 60

1. Run the fit: automl.fit(X_train, y_train)

Actual behavior, stacktrace or logfile

Traceback (most recent call last):
  File "/usr/lib/python3.8/multiprocessing/forkserver.py", line 280, in main
    code = _serve_one(child_r, fds,
  File "/usr/lib/python3.8/multiprocessing/forkserver.py", line 319, in _serve_one
    code = spawn._main(child_r, parent_sentinel)
  File "/usr/lib/python3.8/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
_pickle.UnpicklingError: pickle data was truncated
Traceback (most recent call last):
  File "/usr/lib/python3.8/multiprocessing/forkserver.py", line 280, in main
    code = _serve_one(child_r, fds,
  File "/usr/lib/python3.8/multiprocessing/forkserver.py", line 319, in _serve_one
    code = spawn._main(child_r, parent_sentinel)
  File "/usr/lib/python3.8/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
_pickle.UnpicklingError: pickle data was truncated

Environment and installation:

Please give details about your installation:

• OS: Ubuntu 20.04.2 LTS
• Is your installation in a virtual environment or conda environment? Virtual environment
• Python version: 3.8.10 64-bit
• Auto-sklearn version: 0.12.6