ensemble.ensure_steady_state() is broken

[raven44099]

I really really really admire the person who wrote the tutorial, it is beyond good. Unfortunately I learned fast and so I discovered that somthing is broken. https://github.com/SBRG/masspy/blob/b29701ece7d81b4c5ca073e55e6485f867b7d55d/docs/tutorials/ensemble_modeling.ipynb

In the EM-tutorial, the following cell doesen't work anymore:

feasible, infeasible = ensemble.ensure_steady_state(
    models=positive, strategy="simulate",
    update_values=True, decimal_precision=True)

print("Reached steady state: {0}".format(len(feasible)))
print("No steady state reached: {0}".format(len(infeasible)))

It seems that it works on the official tutorial: https://masspy.readthedocs.io/en/stable/tutorials/ensemble_modeling.html#Simulating-an-Ensemble-of-Models

I used the installation as follows:

%%capture
!pip install masspy==0.1.5
!pip install cobra==0.18.1 #0.18.1

The whole error looks as follows:

``` RuntimeError Traceback (most recent call last) [](https://localhost:8080/#) in 1 feasible, infeasible = ensemble.ensure_steady_state( 2 models=positive, strategy="simulate", ----> 3 update_values=True) 4 # , decimal_precision=True) 5 5 frames [/usr/local/lib/python3.7/dist-packages/mass/simulation/ensemble.py](https://localhost:8080/#) in ensure_steady_state(models, strategy, perturbations, solver_options, update_values, **kwargs) 415 416 simulation = _initialize_simulation( --> 417 models[0], strategy, solver_options, kwargs.get("verbose") 418 ) 419 [/usr/local/lib/python3.7/dist-packages/mass/simulation/ensemble.py](https://localhost:8080/#) in _initialize_simulation(reference_model, strategy, solver_options, verbose) 951 952 """ --> 953 simulation = Simulation(reference_model=reference_model, verbose=verbose) 954 955 if solver_options: [/usr/local/lib/python3.7/dist-packages/mass/simulation/simulation.py](https://localhost:8080/#) in __init__(self, reference_model, id, name, verbose, **kwargs) 192 # Load model into RoadRunner 193 rr = _load_model_into_roadrunner( --> 194 reference_model, rr=None, verbose=verbose, **_SBML_KWARGS 195 ) 196 except MassSimulationError as e: [/usr/local/lib/python3.7/dist-packages/mass/simulation/simulation.py](https://localhost:8080/#) in _load_model_into_roadrunner(mass_model, rr, verbose, **kwargs) 1562 if rr is None: 1563 # Create new roadrunner instance with model -> 1564 rr = roadrunner.RoadRunner(sbml_str) 1565 else: 1566 try: [/usr/local/lib/python3.7/dist-packages/roadrunner/roadrunner.py](https://localhost:8080/#) in _new_init(self, *args) 4424 4425 # Otherwise, use regular init -> 4426 RoadRunner._swig_init(self, *args) 4427 RoadRunner._makeProperties(self) 4428 [/usr/local/lib/python3.7/dist-packages/roadrunner/roadrunner.py](https://localhost:8080/#) in __init__(self, *args) 2709 RoadRunner copy constructor 2710 """ -> 2711 _roadrunner.RoadRunner_swiginit(self, _roadrunner.new_RoadRunner(*args)) 2712 __swig_destroy__ = _roadrunner.delete_RoadRunner 2713 RuntimeError: std::get: wrong index for variant ```