Switch to iris3 testing

[valeriupredoi]

Steps towards validation and inclusion of iris3

Install against source-installed esmvalcore with iris3

• build an esmvalcore environment with the test environment file from https://github.com/ESMValGroup/ESMValCore/pull/819
• update the environment with deps for esmvaltool using env update -n esmvaltool-iris3 -f environment.yml
• install the tool against an already source-installed esmvalcore with iris3 via pip install -e .[develop]
• run tests with pytest -m "not installation" -> all OK

Run some recipes

• repeat steps above to have a working environment with esmvalcore with iris3;
• run some recipes...

Test conda and PyPi package builds

• this is needed in case the conda env update gives different results than conda env create ie there are hidden dependency conflicts that surface only at the stage of env creation; unfortunately this is hard to test unless we release a test esmvalcore package with iris3 - I would honestly think this is not needed and we can just wait until the iris folk have fully released iris3 and take it from there - what do you think @bouweandela ?

[valeriupredoi]

I'd like to ask some peeps to run some recipes but am afraid to do that just now since we'll ask them to run all the recipes for the upcoming esmvaltool 2.1 release next week :grin:

[stefsmeets]

I just tried to run the tests with the iris3 branch of esmvalcore. The good news is that the tests passed right away! The bad idea is that we have no idea how some of the recipes are affected.

I found a few instances of extract_strict, which I have updated (these avoided the tests apparently). I could not find any obvious dimensionless sigmas.

modified:   esmvaltool/cmorizers/obs/nsidc_common.py
modified:   esmvaltool/diag_scripts/autoassess/autoassess_area_base.py
modified:   esmvaltool/diag_scripts/autoassess/land_surface_permafrost/permafrost.py
modified:   esmvaltool/diag_scripts/autoassess/land_surface_surfrad/surfrad.py
modified:   esmvaltool/diag_scripts/shared/_supermeans.py

[stefsmeets]

Created a PR here: #1874

[valeriupredoi]

good stuff, cheers @stefsmeets :beer:

[stefsmeets]

Spent some time looking for the way to install the iris3 branch of esmvaltool, these commands work for me 👍

conda create -n esmvaltool-iris3 -c esmvalgroup -c conda-forge esmvalcore
conda env update -n esmvaltool-iris3 -f environment.yml
pip install -e .[develop]

[bouweandela]

Preferably, it should be possible to install by checking out the branch from #1874, creating a conda environment with the environment.yml from that branch and doing a pip install -e .[develop] for both ESMValTool and ESMValCore (i.e. following the installation from source instructions from the documentation for the iris3 branch).