What happened?

Installing version 0.21.0 from conda-forge results in a ModuleNotFoundError on import (for Python 3.9, at least).

What did you expect to happen?

For xarray to import without crashing.

Minimal Complete Verifiable Example

(base) > conda create -y -n _xarray_bug --override-channels -c conda-forge python=3.9 xarray ... The following NEW packages will be INSTALLED: ... python conda-forge/win-64::python-3.9.10-hcf16a7b_1_cpython ... xarray conda-forge/noarch::xarray-0.21.0-pyhd8ed1ab_0 ... (base) > conda activate _xarray_bug (_xarray_bug) > python -c "import xarray" Traceback (most recent call last): File "<string>", line 1, in <module> File "C:\Anaconda3\envs\_xarray_bug\lib\site-packages\xarray\__init__.py", line 1, in <module> from . import testing, tutorial, ufuncs File "C:\Anaconda3\envs\_xarray_bug\lib\site-packages\xarray\testing.py", line 8, in <module> from xarray.core import duck_array_ops, formatting, utils File "C:\Anaconda3\envs\_xarray_bug\lib\site-packages\xarray\core\duck_array_ops.py", line 24, in <module> from . import dask_array_compat, dask_array_ops, dtypes, npcompat, nputils File "C:\Anaconda3\envs\_xarray_bug\lib\site-packages\xarray\core\dask_array_compat.py", line 4, in <module> from packaging.version import Version ModuleNotFoundError: No module named 'packaging'

Relevant log output

No response

Anything else we need to know?

No response

Environment

(_xarray_bug) > python -c "import xarray as xr;xr.show_versions()" Traceback (most recent call last): File "<string>", line 1, in <module> File "C:\Anaconda3\envs\_xarray_bug\lib\site-packages\xarray\__init__.py", line 1, in <module> from . import testing, tutorial, ufuncs File "C:\Anaconda3\envs\_xarray_bug\lib\site-packages\xarray\testing.py", line 8, in <module> from xarray.core import duck_array_ops, formatting, utils File "C:\Anaconda3\envs\_xarray_bug\lib\site-packages\xarray\core\duck_array_ops.py", line 24, in <module> from . import dask_array_compat, dask_array_ops, dtypes, npcompat, nputils File "C:\Anaconda3\envs\_xarray_bug\lib\site-packages\xarray\core\dask_array_compat.py", line 4, in <module> from packaging.version import Version ModuleNotFoundError: No module named 'packaging'

``` (_xarray_bug) > conda info

 active environment : _xarray_bug
active env location : C:\Anaconda3\envs\_xarray_bug
        shell level : 2
   user config file : C:\Users\Work\.condarc

populated config files : C:\Users\Work.condarc conda version : 4.11.0 conda-build version : 3.21.6 python version : 3.9.7.final.0 virtual packages : __win=0=0 __archspec=1=x86_64 base environment : C:\Anaconda3 (writable) conda av data dir : C:\Anaconda3\etc\conda conda av metadata url : None channel URLs : https://repo.anaconda.com/pkgs/main/win-64 https://repo.anaconda.com/pkgs/main/noarch https://repo.anaconda.com/pkgs/r/win-64 https://repo.anaconda.com/pkgs/r/noarch https://repo.anaconda.com/pkgs/msys2/win-64 https://repo.anaconda.com/pkgs/msys2/noarch package cache : C:\Anaconda3\pkgs C:\Users\Work.conda\pkgs C:\Users\Work\AppData\Local\conda\conda\pkgs envs directories : C:\Anaconda3\envs C:\Users\Work.conda\envs C:\Users\Work\AppData\Local\conda\conda\envs platform : win-64 user-agent : conda/4.11.0 requests/2.26.0 CPython/3.9.7 Windows/10 Windows/10.0.19044 administrator : True netrc file : None offline mode : False

```

``` (_xarray_bug) > conda list

packages in environment at C:\Anaconda3\envs_xarray_bug:

Name Version Build Channel

bzip2 1.0.8 h8ffe710_4 conda-forge ca-certificates 2021.10.8 h5b45459_0 conda-forge importlib-metadata 4.10.1 py39hcbf5309_0 conda-forge importlib_metadata 4.10.1 hd8ed1ab_0 conda-forge intel-openmp 2022.0.0 h57928b3_3663 conda-forge libblas 3.9.0 13_win64_mkl conda-forge libcblas 3.9.0 13_win64_mkl conda-forge libffi 3.4.2 h8ffe710_5 conda-forge liblapack 3.9.0 13_win64_mkl conda-forge libzlib 1.2.11 h8ffe710_1013 conda-forge mkl 2022.0.0 h0e2418a_796 conda-forge numpy 1.22.1 py39h6331f09_0 conda-forge openssl 3.0.0 h8ffe710_2 conda-forge pandas 1.4.0 py39h2e25243_0 conda-forge pip 22.0.2 pyhd8ed1ab_0 conda-forge python 3.9.10 hcf16a7b_1_cpython conda-forge python-dateutil 2.8.2 pyhd8ed1ab_0 conda-forge python_abi 3.9 2_cp39 conda-forge pytz 2021.3 pyhd8ed1ab_0 conda-forge setuptools 60.6.0 py39hcbf5309_0 conda-forge six 1.16.0 pyh6c4a22f_0 conda-forge sqlite 3.37.0 h8ffe710_0 conda-forge tbb 2021.5.0 h2d74725_0 conda-forge tk 8.6.11 h8ffe710_1 conda-forge typing_extensions 4.0.1 pyha770c72_0 conda-forge tzdata 2021e he74cb21_0 conda-forge ucrt 10.0.20348.0 h57928b3_0 conda-forge vc 14.2 hb210afc_6 conda-forge vs2015_runtime 14.29.30037 h902a5da_6 conda-forge wheel 0.37.1 pyhd8ed1ab_0 conda-forge xarray 0.21.0 pyhd8ed1ab_0 conda-forge xz 5.2.5 h62dcd97_1 conda-forge zipp 3.7.0 pyhd8ed1ab_0 conda-forge ```