fix: expose env variable for workspace

jina/optimizers/__init__.py

@@ -27,6 +27,7 @@ def get_empty_copy(self) -> 'OptimizerCallback':
         """
         Return an empty copy of the :class:`OptimizerCallback`.
 
+        .. # noqa: DAR202
         :raises NotImplementedError: :class:`OptimizerCallback` is just an interface. Please use any implemented subclass.
         """
         raise NotImplementedError
@@ -35,6 +36,7 @@ def get_final_evaluation(self) -> float:
         """
         Return the aggregation of all evaluation collected via :method:`__call__`
 
+        .. # noqa: DAR202
         :raises NotImplementedError: :class:`OptimizerCallback` is just an interface. Please use any implemented subclass.
         """
         raise NotImplementedError
@@ -187,6 +189,8 @@ def _trial_parameter_sampler(self, trial):
         trial.workspace = self._workspace_base_dir + '/JINA_WORKSPACE_' + '_'.join(
             [str(v) for v in trial_parameters.values()])
 
+        trial_parameters['JINA_OPTIMIZER_TRIAL_WORKSPACE'] = trial.workspace
+
         return trial_parameters
 
     @staticmethod