Variious tests fail on x86 (32-bit issues)?

[eli-schwartz]

What happened?

FAILED xarray/tests/test_formatting.py::TestFormatting::test_diff_datatree_repr_equals - assert "Left and right DataTree objects are not equal\n\nData at node 'node' does not match:\n    Differing dimensions:\n        (y: 2) != (x: 1, y: 2)\n    Differing data variables:\n    L   data     (y) i...
FAILED xarray/tests/test_formatting.py::test_repr_pandas_multi_index - assert "<xarray.DataArray 'x' (x: 4)> Size: 16B\n[4 values with dtype=object]\nCoordinates:\n  * x        (x) object 16B MultiIndex\n  * foo      (x) object 16B 'a' 'a' 'b' 'b'\n  * bar      (x) int64 32B 1...
FAILED xarray/tests/test_coding_times.py::test_decode_timedelta_via_units[decode_timedelta=False] - AssertionError: assert dtype('int32') == dtype('int64')
FAILED xarray/tests/test_variable.py::TestVariable::test_reduce_keepdims - AssertionError: Left and right Variable objects are not identical
FAILED xarray/tests/test_groupby.py::test_groupby_reduce_dimension_error - AssertionError: Left and right DataArray objects are not identical
FAILED xarray/tests/test_groupby.py::TestDataArrayGroupBy::test_groupby_reduce_keep_attrs[None-True] - AssertionError: Left and right DataArray objects are not identical
FAILED xarray/tests/test_groupby.py::TestDataArrayGroupBy::test_groupby_reduce_keep_attrs[None-False] - AssertionError: Left and right DataArray objects are not identical
FAILED xarray/tests/test_groupby.py::TestDataArrayGroupBy::test_groupby_reduce_keep_attrs[True-True] - AssertionError: Left and right DataArray objects are not identical
FAILED xarray/tests/test_groupby.py::TestDataArrayGroupBy::test_groupby_reduce_keep_attrs[True-False] - AssertionError: Left and right DataArray objects are not identical
FAILED xarray/tests/test_groupby.py::TestDataArrayGroupBy::test_groupby_reduce_keep_attrs[False-True] - AssertionError: Left and right DataArray objects are not identical
FAILED xarray/tests/test_groupby.py::TestDataArrayGroupBy::test_groupby_reduce_keep_attrs[False-False] - AssertionError: Left and right DataArray objects are not identical
FAILED xarray/tests/test_namedarray.py::test_fake_target_chunksize[input_array0-1024-int64] - AssertionError: assert dtype('int32') == <class 'numpy.int64'>
FAILED xarray/tests/test_namedarray.py::test_fake_target_chunksize_cftime - assert 146 == 73
FAILED xarray/tests/test_dataset.py::TestDataset::test_to_and_from_dataframe - assert False
FAILED xarray/tests/test_strategies.py::TestReduction::test_mean - AssertionError: 
========================================================= 15 failed, 12970 passed, 6493 skipped, 26 xfailed, 9 xpassed, 12 warnings in 178.95s (0:02:58) ==========================================================
 * ERROR: dev-python/xarray-2025.11.0::gentoo failed (test phase):
 *   pytest failed with python3.13

Seems to be bad hardcoded assumptions? Tests all pass on amd64.

Verbose log: xarray-2025.11.0:20251128-074341.log

Steps to reproduce

In an x86 Gentoo container:

emerge --onlydeps --with-test-deps dev-python/xarray
FEATURES=test emerge dev-python/xarray

MVCE confirmation

• [ ] Minimal example — the example is as focused as reasonably possible to demonstrate the underlying issue in xarray.
• [ ] Complete example — the example is self-contained, including all data and the text of any traceback.
• [ ] Verifiable example — the example copy & pastes into an IPython prompt or Binder notebook, returning the result.
• [ ] New issue — a search of GitHub Issues suggests this is not a duplicate.
• [ ] Recent environment — the issue occurs with the latest version of xarray and its dependencies.

Environment

>>> import xarray as xr >>> xr.show_versions()

INSTALLED VERSIONS

commit: None python: 3.13.5 (main, Nov 28 2025, 05:01:36) [GCC 14.3.1 20250801] python-bits: 32 OS: Linux OS-release: 6.17.3-gentoo-dist machine: i686 processor: AMD EPYC 7543 32-Core Processor byteorder: little LC_ALL: None LANG: C.UTF-8 LOCALE: ('C', 'UTF-8') libhdf5: 1.14.6 libnetcdf: None

xarray: 2025.11.0 pandas: 2.3.1 numpy: 2.3.2 scipy: 1.16.2 netCDF4: None pydap: None h5netcdf: None h5py: 3.15.1 zarr: None cftime: 1.6.5 nc_time_axis: None iris: None bottleneck: 1.6.0 dask: None distributed: None matplotlib: 3.10.3 cartopy: None seaborn: None numbagg: None fsspec: None cupy: None pint: None sparse: None flox: None numpy_groupies: None setuptools: 80.9.0 pip: 25.3 conda: None pytest: 8.4.2 mypy: None IPython: None sphinx: None

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