The arguments of sagemaker.estimator.Estimator() and sagemaker.tuner.HyperparameterTuner() doesn't accept ExecutionInput or StepInput as placeholder. E.g. for the output_path of sagemaker.estimator.Estimator() has to be fixed in the definition of workflow.

The current way around this is not to make use of stepfunctions.steps.sagemaker.TuningStep and use the generic step functions.steps.Task to invoke the arn:aws:states:::sagemaker:createHyperParameterTuningJob.sync with parameters from ExecutionInput and StepInput