tox fails with py36. (succeeds with py27 though)

[aaron-mcdaid-zalando]

6 failed, 110 passed in 72.82 seconds

Here is one of those six failed tests:

______________________________________________________________________________ BayesFactorTestCases.test_bayes_factor_with_nan_input _______________________________________________________________________________

self = <tests.tests_core.test_early_stopping.BayesFactorTestCases testMethod=test_bayes_factor_with_nan_input>

    def test_bayes_factor_with_nan_input(self):
        """ Check the Bayes factor function with input that contains nan values."""
>       res = es.bayes_factor(self.rand_s5, self.rand_s6, num_iters=2000)

tests/tests_core/test_early_stopping.py:132:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
expan/core/early_stopping.py:273: in bayes_factor
    inference=inference)
expan/core/early_stopping.py:223: in _bayes_sampling
    control={'stepsize': 0.01, 'adapt_delta': 0.99})
.tox/py36/lib/python3.6/site-packages/pystan/model.py:671: in sampling
    fit = self.fit_class(data)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

>   ???
E   TypeError: __init__() takes exactly 2 positional arguments (1 given)

stanfit4anon_model_d87af3570eba8e4d47ba3c301c4f7a1d_6351398166046700535.pyx:463: TypeError
----------------------------------------------------------------------------------------------- Captured stderr call -----------------------------------------------------------------------------------------------
INFO:expan.core.early_stopping:Started running bayes factor with 1000 procedure, treatment group of size 1000, control group of size normal, sampling distribution.
INFO:expan.core.early_stopping:Started running bayesian inference with sampling procedure, treatment group of size 1000, control group of size 1000, normal distribution.
INFO:expan.core.early_stopping:Started loading and compiling Stan model for normal distribution

[shansfolder]

@aaron-mcdaid-zalando works for me.

It could be tox cached an old version of pystan for you. Try delete .tox directory and run again. :)