Add xesmf to the standard python environment

[glemieux]

Description of changes

In preparation for adding the fates luh2 data tooling to the ctsm5.2 makefile, this PR adds the xesmf package to the standard ctsm_pylib environment.

Specific notes

See glemieux/fates#25 (comment) for details about compatibility issues with numba, which is a requirement of xesmf.

Contributors other than yourself, if any:

CTSM Issues Fixed (include github issue #):

Are answers expected to change (and if so in what way)? N/A

Any User Interface Changes (namelist or namelist defaults changes)?

Testing performed, if any: test that conda install works.

[glemieux]

@ekluzek I drafted this so that I could share my branch and the change easily. I wasn't sure if you'd want to merge this locally to your #2008 branch in preparation for adding the fates luh2 datatool call in NGEET/fates#1032 to the Makefile.data or make this an actual PR that I would test and we would bring to master first.

[glemieux]

I ran the python tests against the updated standard conda environment using make all in the python directory. Everything looks good:

(ctsm_pylib) ✔  ~/ctsm/python [python/xesmf-add {glemieux/python/xesmf-add}|⚑ 14] 
11:21 $ make all
python3 ./run_ctsm_py_tests  --unit
.....................................................................................................................................................................
----------------------------------------------------------------------
Ran 165 tests in 0.870s

OK
python3 ./run_ctsm_py_tests  --sys
...............Setting resource.RLIMIT_STACK to -1 from (307200000, -1)
Done converting /glade/scratch/glemieux/tmpwmp957eb/scrip.nc
.
----------------------------------------------------------------------
Ran 16 tests in 11.545s

OK
pylint -j 4 --rcfile=ctsm/.pylintrc ctsm

--------------------------------------------------------------------
Your code has been rated at 10.00/10 (previous run: 10.00/10, +0.00)

black --check --config pyproject.toml . ../cime_config/SystemTests ../cime_config/buildlib ../cime_config/buildnml
All done! ✨ 🍰 ✨
75 files would be left unchanged.

Still waiting for the latest conda environment build to solve before testing that out.

[glemieux]

Running tests with the "latest" conda environment has issues with making black:

(ctsm_pylib) ✔  ~/ctsm/python [python/xesmf-add {glemieux/python/xesmf-add}|⚑ 14] 
14:26 $ make all
python3 ./run_ctsm_py_tests  --unit
.....................................................................................................................................................................
----------------------------------------------------------------------
Ran 165 tests in 2.253s

OK
python3 ./run_ctsm_py_tests  --sys
...............copying /glade/u/home/glemieux/ctsm/ccs_config/machines/Depends.intel -> /glade/scratch/glemieux/tmpocrq60_5
Setting resource.RLIMIT_STACK to -1 from (307200000, -1)
Done converting /glade/scratch/glemieux/tmpocrq60_5/scrip.nc
.
----------------------------------------------------------------------
Ran 16 tests in 84.212s

OK
pylint -j 4 --rcfile=ctsm/.pylintrc ctsm

--------------------------------------------------------------------
Your code has been rated at 10.00/10 (previous run: 10.00/10, +0.00)

black --check --config pyproject.toml . ../cime_config/SystemTests ../cime_config/buildlib ../cime_config/buildnml
would reformat ../cime_config/buildlib
would reformat /glade/u/home/glemieux/ctsm/python/ctsm/test/test_unit_utils_add_tag.py
would reformat /glade/u/home/glemieux/ctsm/python/ctsm/modify_input_files/modify_mesh_mask.py
would reformat ../cime_config/buildnml
would reformat /glade/u/home/glemieux/ctsm/python/ctsm/toolchain/ctsm_case.py
would reformat /glade/u/home/glemieux/ctsm/python/ctsm/modify_input_files/modify_fsurdat.py
would reformat /glade/u/home/glemieux/ctsm/python/ctsm/test/test_unit_run_sys_tests.py
would reformat /glade/u/home/glemieux/ctsm/python/ctsm/site_and_regional/single_point_case.py
would reformat /glade/u/home/glemieux/ctsm/python/six.py

Oh no! 💥 💔 💥
9 files would be reformatted, 66 files would be left unchanged.
Makefile:53: recipe for target 'black' failed
make: *** [black] Error 1

[negin513]

I am happy to xesmf this rolling in as a dependecy. xesmf is an outstanding package, and the entire regrid functionality (aka toolchain) could have been easily developed with it for a pure Python framework without any need to call the fortran binaries from inside the python! 😉
However, there was strong opposition against using xesmf!
Happy to see the progress!