Tests were disabled years ago by 140136ad95 (mdp: disable tests,
2017-09-14) because of missing dependencies that are not in nixpkgs, but
current version 3.6 prints a warning and run the tests just fine.
============================= test session starts ==============================
platform darwin -- Python 3.9.6, pytest-6.2.5, py-1.10.0, pluggy-1.0.0
python: 3.9.6.final.0
mdp: 3.6
parallel python: NOT AVAILABLE: No module named 'pp'
shogun: NOT AVAILABLE: No module named 'shogun'
libsvm: NOT AVAILABLE: No module named 'libsvm'
joblib: NOT AVAILABLE: No module named 'joblib'
sklearn: NOT AVAILABLE: No module named 'scikits'
numx: numpy 1.21.2
symeig: symeig_fake
Random Seed: 7710873