New pint version (0.24) breaks units

[Zeitsperre]

• xclim version: 0.49.0
• Python version: All
• Operating System: Any

Description

The latest pint is causing xclim to error-out on import. We need to pin the library and perform a patch release, then adapt to the new API.

[aulemahal]

Is there a log we can see somewhere ?
On my machine, I installed a mamba env from xclim's environment.yml and then did pip install "pint >=0.24". In this setup, importing xclim works and a basic convert_units_to call does too.

[aulemahal]

Running the tests I see the following:

__________________________________________________________________________________________ ERROR at setup of TestPWMFit.test_pwm_fit[True-pearson3] __________________________________________________________________________________________
[gw0] linux -- Python 3.12.3 /home/pbourg/mambaforge/envs/xclim/bin/python3.12

threadsafe_data_dir = PosixPath('/tmp/pytest-of-pbourg/pytest-0/popen-gw0/data'), worker_id = 'gw0'
xdoctest_namespace = {'np': <module 'numpy' from '/home/pbourg/mambaforge/envs/xclim/lib/python3.12/site-packages/numpy/__init__.py'>, 'ope.../xclim/xclim/__init__.py'>, 'xr': <module 'xclim.testing' from '/home/pbourg/Projets/xclim/xclim/testing/__init__.py'>}

    @pytest.fixture(scope="session", autouse=True)
    def gather_session_data(threadsafe_data_dir, worker_id, xdoctest_namespace):
        """Gather testing data on pytest run.
    
        When running pytest with multiple workers, one worker will copy data remotely to _default_cache_dir while
        other workers wait using lockfile. Once the lock is released, all workers will then copy data to their local
        threadsafe_data_dir.As this fixture is scoped to the session, it will only run once per pytest run.
    
        Additionally, this fixture is also used to generate the `atmosds` synthetic testing dataset as well as add the
        example file paths to the xdoctest_namespace, used when running doctests.
        """
        if (
            not _default_cache_dir.joinpath(helpers.TESTDATA_BRANCH).exists()
            or helpers.PREFETCH_TESTING_DATA
        ):
            if helpers.PREFETCH_TESTING_DATA:
                print("`XCLIM_PREFETCH_TESTING_DATA` set. Prefetching testing data...")
            if sys.platform == "win32":
                raise OSError(
                    "UNIX-style file-locking is not supported on Windows. "
                    "Consider running `$ xclim prefetch_testing_data` to download testing data."
                )
            elif worker_id in ["master"]:
                helpers.populate_testing_data(branch=helpers.TESTDATA_BRANCH)
            else:
                _default_cache_dir.mkdir(exist_ok=True, parents=True)
                lockfile = _default_cache_dir.joinpath(".lock")
                test_data_being_written = FileLock(lockfile)
                with test_data_being_written:
                    # This flag prevents multiple calls from re-attempting to download testing data in the same pytest run
                    helpers.populate_testing_data(branch=helpers.TESTDATA_BRANCH)
                    _default_cache_dir.joinpath(".data_written").touch()
                with test_data_being_written.acquire():
                    if lockfile.exists():
                        lockfile.unlink()
        shutil.copytree(_default_cache_dir, threadsafe_data_dir)
>       helpers.generate_atmos(threadsafe_data_dir)

tests/conftest.py:500: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
xclim/testing/helpers.py:90: in generate_atmos
    rsus = shortwave_upwelling_radiation_from_net_downwelling(ds.rss, ds.rsds)
xclim/core/units.py:1291: in wrapper
    out = func(*args, **kwargs)
xclim/indices/_conversion.py:1140: in shortwave_upwelling_radiation_from_net_downwelling
    rss = convert_units_to(rss, rsds)
xclim/core/units.py:328: in convert_units_to
    target_cf_unit = pint2cfunits(target_unit)
xclim/core/units.py:190: in pint2cfunits
    return f"{value:cf}".replace("dimensionless", "")
../../mambaforge/envs/xclim/lib/python3.12/site-packages/pint/facets/plain/unit.py:67: in __format__
    return self._REGISTRY.formatter.format_unit(self, spec)
../../mambaforge/envs/xclim/lib/python3.12/site-packages/pint/delegates/formatter/full.py:129: in format_unit
    return self.get_formatter(uspec).format_unit(
../../mambaforge/envs/xclim/lib/python3.12/site-packages/pint/delegates/formatter/_to_register.py:102: in format_unit
    return func(units, registry=self._registry)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

unit = <UnitsContainer({'meter': -2, 'watt': 1})>, registry = None, options = {}, re = <module 're' from '/home/pbourg/mambaforge/envs/xclim/lib/python3.12/re/__init__.py'>

    @pint.register_unit_format("cf")
    def short_formatter(unit, registry, **options):
        """Return a CF-compliant unit string from a `pint` unit.
    
        Parameters
        ----------
        unit : pint.UnitContainer
            Input unit.
        registry : pint.UnitRegistry
            the associated registry
        **options
            Additional options (may be ignored)
    
        Returns
        -------
        out : str
            Units following CF-Convention, using symbols.
        """
        import re
    
        # convert UnitContainer back to Unit
>       unit = registry.Unit(unit)
E       AttributeError: 'NoneType' object has no attribute 'Unit'

../../mambaforge/envs/xclim/lib/python3.12/site-packages/cf_xarray/units.py:38: AttributeError

which looks like indeed a pint error, but stemming from cf-xarray rather than xclim ?

The nightly CI of cf-xarray has failed indeed xarray-contrib/cf-xarray#507.

[aulemahal]

I have opened an issue in pint, asking questions about the change hgrecco/pint#2009.