python-pingouin fails to build with Python 3.9.0a4.

>       assert pt.drop(columns=['Time']).iloc[0:4, :].equals(pt_no_inter)
E       AssertionError: assert False
E        +  where False = <bound method NDFrame.equals of   Contrast        A           B Paired  ...  p-corr  p-adjust   BF10 hedges\n0     Time... holm  0.288 -0.170\n3    Group  Control  Meditation  False  ...     NaN       NaN  1.813 -0.340\n\n[4 rows x 13 columns]>(  Contrast        A           B  Paired  ...  p-corr  p-adjust   BF10 hedges\n0     Time   August     January   False  ... holm  0.288 -0.170\n3    Group  Control  Meditation   False  ...     NaN       NaN  1.813 -0.340\n\n[4 rows x 13 columns])
E        +    where <bound method NDFrame.equals of   Contrast        A           B Paired  ...  p-corr  p-adjust   BF10 hedges\n0     Time... holm  0.288 -0.170\n3    Group  Control  Meditation  False  ...     NaN       NaN  1.813 -0.340\n\n[4 rows x 13 columns]> =   Contrast        A           B Paired  ...  p-corr  p-adjust   BF10 hedges\n0     Time   August     January  False  .....  holm  0.288 -0.170\n3    Group  Control  Meditation  False  ...     NaN       NaN  1.813 -0.340\n\n[4 rows x 13 columns].equals
df         =        Scores    Time       Group  Subject
0    5.971435  August     Control        0
1    4.309024  August     Contro...       57
178  4.990568    June  Meditation       58
179  7.822986    June  Meditation       59
[180 rows x 4 columns]
pt         =        Contrast     Time        A           B  ... p-corr  p-adjust   BF10  hedges
0          Time        -   August  ...0.619  -0.365
6  Time * Group     June  Control  Meditation  ...  0.024      holm  5.593  -0.699
[7 rows x 14 columns]
pt_no_inter =   Contrast        A           B  Paired  ...  p-corr  p-adjust   BF10 hedges
0     Time   August     January   False  ... holm  0.288 -0.170
3    Group  Control  Meditation   False  ...     NaN       NaN  1.813 -0.340
[4 rows x 13 columns]
self       = <pingouin.tests.test_pairwise.TestPairwise testMethod=test_pairwise_ttests>
pingouin/tests/test_pairwise.py:56: AssertionError



>       if isinstance(data.columns, pd.core.index.MultiIndex):
E       AttributeError: module 'pandas.core' has no attribute 'index'
columns    = ['X', 'M', 'Y']
corr       = <function corr at 0x7ff99f2f2ee0>
covar      = None
data       =     X  M  Y  Mbin  Ybin
0   6  5  6     0     1
1   7  5  5     1     0
2   7  7  4     0     0
3   8  4  8     0     ...96  8  4  1     1     0
97  7  4  5     0     0
98  2  2  1     0     1
99  5  4  5     0     0
[100 rows x 5 columns]
export_filename = None
keys       = ['X', 'M', 'Y', 'Mbin', 'Ybin']
method     = 'spearman'
nan_policy = 'pairwise'
padjust    = 'none'
partial_corr = <function partial_corr at 0x7ff99f2f2f70>
tail       = 'two-sided'
traverse   = <function pairwise_corr.<locals>.traverse at 0x7ff99536fdc0>
pingouin/pairwise.py:965: AttributeError

For the build logs, see:
https://copr-be.cloud.fedoraproject.org/results/@python/python3.9/fedora-rawhide-x86_64/01256792-python-pingouin/

For all our attempts to build python-pingouin with Python 3.9, see:
https://copr.fedorainfracloud.org/coprs/g/python/python3.9/package/python-pingouin/

Testing and mass rebuild of packages is happening in copr. You can follow these instructions to test locally in mock if your package builds with Python 3.9:
https://copr.fedorainfracloud.org/coprs/g/python/python3.9/

Let us know here if you have any questions.

Python 3.9 will be included in Fedora 33. To make that update smoother, we're building Fedora packages with early pre-releases of Python 3.9.
A build failure prevents us from testing all dependent packages (transitive [Build]Requires), so if this package is required a lot, it's important for us to get it fixed soon.
We'd appreciate help from the people who know this package best, but if you don't want to work on this now, let us know so we can try to work around it on our side.