Find netcdf and pnetcdf with env vars on Chicoma and PM

[xylar]

This is necessary because the nc-config executable (and equivalents for the other libraries) cannot be used to locate the correct path for the libraries relative to the bin directory.

Checklist

• Document (in a comment titled Testing in this PR) any testing that was used to verify the changes

[xylar]

Testing

With these changes, I am able to compile MPAS-Ocean on Chicoma and Perlmutter. Without them, the netcdf and pnetcdf libraries are not found (see #523 (comment)).

I also successfully ran the nightly test suite on Perlmutter. It is in the queue on Chicoma. Stay tuned...

[xylar]

@mark-petersen, this is ready for you to try.

[xylar]

@darincomeau and @mark-petersen, please cherry-pick this commit when you test #523

[mark-petersen]

This worked for me on chicoma. Specifically, I started with the compass repo on #523, cherry-picked this commit, then:

rm -rf /lustre/scratch5/mpeterse/spack_test
rm -rf /lustre/scratch5/mpeterse/spack_tmp
export  CONDA_BASE=/usr/projects/climate/mpeterse/miconda3

./conda/configure_compass_env.py \
    --conda ${CONDA_BASE}  \
      --update_spack \
     --spack /lustre/scratch5/mpeterse/spack_test \
    --tmpdir /lustre/scratch5/mpeterse/spack_tmp  \
   --compiler gnu  \
   --recreate

note that I did not use

--mache_fork xylar/mache     --mache_branch update_cime_machines

, and this presumably defaults to

--mache_fork E3SM-Project/mache     --mache_branch main

Regardless, this finds the correct netcdf and pnetcdf paths on chicoma. I was able to compile with gnu debug and run a nightly test suite.

[xylar]

@mark-petersen, thanks for testing!

and this presumably defaults to
--mache_fork E3SM-Project/mache --mache_branch main

No, that's not quite right. It defaults to getting mache from the latest release (from a conda package rather than the repository). So in the future you would need to explicitly put in that fork and branch to test with main, rather than the release. What you did is fine for testing this PR but doesn't test #523.

[darincomeau]

Approved based on testing with #523 on Perlmutter.

[xylar]

Thanks @darincomeau!