Esmvaltool: pip error when following installation instructions in CONTRIBUTING.md

[bascrezee]

Following the installation instructions as described in https://github.com/ESMValGroup/ESMValTool/blob/master/CONTRIBUTING.md

When executing pip install -e '.[develop]'

ERROR: Could not find a version that satisfies the requirement esmvalcore<2.1,>=2.0.0b6 (from ESMValTool==2.0.0b2) (from versions: none)
ERROR: No matching distribution found for esmvalcore<2.1,>=2.0.0b6 (from ESMValTool==2.0.0b2)

One should first install esmvalcore (I install it in development mode, but I guess anything would work), before installing ESMValTool. I opened a draft PR #1564 to show what instructions fixed the problem for me. I am not sure if these are the right instructions, but this shows the problem (when following old instructions) and how to fix it (new instructions).

[bouweandela]

It looks like you may have forgotten to run the step right before the pip install .. in the instructions:

• Create the esmvaltool conda environment conda env create --name esmvaltool --file environment.yml

because ESMValCore is usually installed from conda. Installing from source is described in the next section.

[valeriupredoi]

no - the problem here is when you create the environment from esmvalcore's environment.yml and then try to install esmvaltool in it before (and probably forgetting to? or using an obsolete version of?) pip install -e . in esmvalcore - hence @bascrezee instructions in #1564

[bascrezee]

There are quite a few steps in the installation, and I did my very best to follow them carefully. @valeriupredoi I did not create from esmvalcore's environment.yml, I created from esmvaltool's environment.yml as mentioned in the instructions. I also did the whole procedure from the start a few times (removing the environment in between) to make sure that I did not make any mistakes. I am running conda 4.8.2.

[bouweandela]

Hi Bas,

Sometimes conda silently fails to activate an environment even if you type conda activate environment_name. Maybe you can try deactivating and activating the esmvaltool environment again before running pip install?

The command conda env create --name esmvaltool --file environment.yml creates an environment called esmvaltool containing the packages listed in environment.yml. If you open that file, you will see the esmvalcore package listed in there. You can check that it is correctly installed in the conda environment called esmvaltool by running conda env export --name esmvaltool

[valeriupredoi]

Bit of a less text-verbose way to check is conda list esmvalcore

[bascrezee]

Sometimes conda silently fails to activate an environment

This is a bit worrying ! But good to know.

And maybe this is indeed what happened yesterday. I tried again, following your instructions and now everything works fine. The conda env export --name esmvaltool contains:

- esmvalcore=2.0.0b7=py_0

Everything good. @valeriupredoi shall we close this and #1564 ? Or do you want to address something else ?

[valeriupredoi]

Nah am good bro, cheers for the extra detective work tho :beer:

[bascrezee]

Cheers :coffee: