add xscen recipe

[Zeitsperre]

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[conda-forge-webservices]

Hi! This is the friendly automated conda-forge-linting service.

I wanted to let you know that I linted all conda-recipes in your PR (xscen) and found some lint.

Here's what I've got...

For xscen:

• Please do not delete the example recipe found in recipes/example/meta.yaml.

[Zeitsperre]

@aulemahal @juliettelavoie @RondeauG

Can you all confirm that you wish to be maintainers? Thanks!

[conda-forge-webservices]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipes/xscen) and found it was in an excellent condition.

[Zeitsperre]

@aulemahal Am I correct in assuming that xesmf does not support Windows?

[aulemahal]

You are correct.

[Zeitsperre]

@conda-forge/help-python

Should I be skipping windows explicitly, or should I leave this as noarch: python?

This PR is otherwise ready!

[aulemahal]

We could remove xESMF as a hard dependency and make the whole "regrid" submodule optional. I would do that only on windows though, not sure if that's a good conda-forge practice.

[Zeitsperre]

You can set optional dependencies depending on the platform. This is very much allowed in conda-forge. The question is whether we would want to add this to the xscen package. It's entirely doable, and it would enable Windows users to use (most) of the functionality.

We could open an issue about this in xscen.

[aulemahal]

I just found out that windows build are made for ESMF since February. Sorry for the false alarm, xscen seems to be usable on all three OSs!

[aulemahal]

The CI failure seems to be due to esmf-org/esmf#117.

It is interesting that this doesn't happen on the cool OSs.

But anyway, this bug is fixed on ESMF 8.5 which is on the way for a conda-forge release.

[ocefpaf]

I just found out that windows build are made for ESMF since February. Sorry for the false alarm, xscen seems to be usable on all three OSs!

conda-forge doesn't build ESMF on Windows yet. We couldn't make it work. You can still publish this as noarch and leave the Windows to "error out" at install time, or make ESMF optional internally with some lazy import and make xscen partially funcional on Windows. It all depends on how important ESMF is for this package.

[aulemahal]

Hum, on our part making (x)ESMF optional is quite easy, but I think we have one dependency (clisops) that also required xESMF.

But, I was able to install ESMF on a windows machine using mamba a few minutes ago. And a win-64 build is listed here : https://anaconda.org/conda-forge/esmf. Were those uploaded manually rather then through the automated conda-forge process ?

The Windows build fails because of a missing environment variable, but the package was indeed installed before that error.

[ocefpaf]

But, I was able to install ESMF on a windows machine using mamba a few minutes ago. And a win-64 build is listed here : https://anaconda.org/conda-forge/esmf. Were those uploaded manually rather then through the automated conda-forge process ?

Nope. My memory failed me. It was added a while back in conda-forge/esmf-feedstock#65

In theory you are good to go here.

[Zeitsperre]

@ocefpaf

I think we can adjust the remaining changes needed within xscen. Our target OS is primarily *nix, so if we can get Windows working within the next release of xscen, that's a bonus. All maintainers have indicated their intent to manage this library. Please feel free to merge!

Thanks!

[ocefpaf]

The missing env var, ESMFMKFILE should probablt be set in the ESMF feedstock. Can you open an issue there so we can track that?