try to make failing tests running

mlair/run_modules/post_processing.py

@@ -10,7 +10,6 @@ import sys
 import traceback
 import pathos
 import multiprocess.context as ctx
-ctx._force_start_method('spawn')
 import psutil
 from typing import Dict, Tuple, Union, List, Callable
 
@@ -699,6 +698,15 @@ class PostProcessing(RunEnvironment):
         logging.info(f"start train_ols_model on train data")
         self.ols_model = OrdinaryLeastSquaredModel(self.train_data)
 
+    @staticmethod
+    def _get_ctx_context():
+        _default_context = ctx._default_context
+        if _default_context._actual_context is None:
+            _actual_context = _default_context._default_context._name
+        else:
+            _actual_context = ctx._default_context._actual_context._name
+        return _actual_context
+
     @TimeTrackingWrapper
     def make_prediction(self, subset):
         """
@@ -719,6 +727,8 @@ class PostProcessing(RunEnvironment):
         n_process = min([psutil.cpu_count(logical=False), len(subset), max_process])  # use only physical cpus
         if n_process > 1 and use_multiprocessing is True:  # parallel solution
             logging.info("use parallel make prediction approach")
+            _actual_context = self._get_ctx_context()
+            ctx._force_start_method('spawn')
             pool = pathos.multiprocessing.ProcessingPool(n_process)
             logging.info(f"running {getattr(pool, 'ncpus')} processes in parallel")
             output = [
@@ -732,6 +742,7 @@ class PostProcessing(RunEnvironment):
             pool.close()
             pool.join()
             pool.clear()
+            ctx._force_start_method(_actual_context)
         else:  # serial solution
             logging.info("use serial make prediction approach")
             for i, data in enumerate(subset):