The package currently fails its test on i386 and armhf. The culprit is
the cython function partial_wasserstein_1d_cy (defined in
ot/partial/partial_cython.pyx), which tries to store the return type of
np.argsort as an ndarray with entries of type np.int64_t. I believe the
array returned by argsort has 32 bit entries on those architectures.

While this particular instance of the problem should be easy to fix in
order to make the test pass, upstream has in the past indicated [1] that
they have no desire to support 32 bit platforms. It is therefore likely
that the same type of issue exists elsewhere in parts of the code that
don't undergo autopkgtests. Fixing the test would then likely just be
papering over real issues.

Unless someone has good motivation to tackle the issue holistically, or
to convince upstream to take these platforms seriously, I suggest we
drop 32 bit architectures for this package going forward.

[1] https://github.com/PythonOT/POT/issues/521


 Best,
 Gard