[Debian-astro-maintainers] Bug#1029688: emcee: test failure with scipy 1.10

[Drew Parsons]

Package: emcee
Version: 3.1.3-1
Severity: normal

scipy 1.10 is now available in experimental. 
emcee fails debci tests using it.


We are considering uploading scipy 1.10 to unstable in order to
included it in the forthcoming stable release.  If we proceed with
that, then this bug will become Severity: serious.

The errors are IndexErrors. A sample from the failing test log is

_______________________________ test_uniform_de ________________________________

kwargs = {}

    def test_uniform_de(**kwargs):
>       _test_uniform(moves.DEMove(), **kwargs)

/usr/lib/python3/dist-packages/emcee/tests/integration/test_de.py:19: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
/usr/lib/python3/dist-packages/emcee/tests/integration/test_proposal.py:101: in _test_uniform
    ks, _ = stats.kstest(samps[::100], "uniform")
/usr/lib/python3/dist-packages/scipy/_lib/_util.py:700: in wrapper
    return fun(*args, **kwargs)
/usr/lib/python3/dist-packages/scipy/stats/_stats_py.py:8383: in kstest
    return ks_1samp(xvals, cdf, args=args, alternative=alternative,
/usr/lib/python3/dist-packages/scipy/_lib/_util.py:700: in wrapper
    return fun(*args, **kwargs)
/usr/lib/python3/dist-packages/scipy/stats/_stats_py.py:7759: in ks_1samp
    Dplus, dplus_location = _compute_dplus(cdfvals, x)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

cdfvals = array([[0.3753341 ],
       [0.        ],
       [0.        ],
       [0.        ],
       [0.        ],
       [0.168...[0.89123376],
       [1.        ],
       [0.55866734],
       [0.74500648],
       [0.        ],
       [0.        ]])
x = array([[ 0.3753341 ],
       [-1.0110354 ],
       [-0.56077189],
       [-0.90308162],
       [-0.99837366],
       [...123376],
       [ 2.13529302],
       [ 0.55866734],
       [ 0.74500648],
       [-0.65506003],
       [-0.83396273]])

    def _compute_dplus(cdfvals, x):
        """Computes D+ as used in the Kolmogorov-Smirnov test.
    
        Parameters
        ----------
        cdfvals : array_like
            Sorted array of CDF values between 0 and 1
        x: array_like
            Sorted array of the stochastic variable itself
    
        Returns
        -------
        res: Pair with the following elements:
            - The maximum distance of the CDF values below Uniform(0, 1).
            - The location at which the maximum is reached.
    
        """
        n = len(cdfvals)
        dplus = (np.arange(1.0, n + 1) / n - cdfvals)
        amax = dplus.argmax()
>       loc_max = x[amax]
E       IndexError: index 1279 is out of bounds for axis 0 with size 640

/usr/lib/python3/dist-packages/scipy/stats/_stats_py.py:7586: IndexError