Add capability to set an extra spec

[adriendelsalle]

Description

A way to add extra specs and pinning depending on variables (python matrix build, etc.) would be to pass extra specs to micromamba command: micromamba create -n <env-name> -f <spec-file> <extra-specs>

[wolfv]

did you compile the program using npm run build?

[wolfv]

https://github.com/mamba-org/provision-with-micromamba#development

[wolfv]

btw you probably need to rebase now as I merged some stuff.

[beckermr]

Why do we need this PR? You can simply install the extra spec yourself using micromamba in the activated env, right?

[adriendelsalle]

@beckermr the use case is

• having a environment.yml file with python or pybind11, without pinning Python version
• you want a matrix build for several Python versions

Then you don't want to install everything then solve again (+download, extract, link..) to downgrade all packages right?
You see better approaches?

[beckermr]

I see what you mean for the double solves. I guess I am ok with that but this does seem like a nice hook for optimization. Thanks for the PR!

[wolfv]

I wonder if we should add quoting or if we should accept a list of specs here and then quote each on individually

[wolfv]

Because there is the issue with 'python>=3.8' being a bash redirection

[adriendelsalle]

good question, I was also wondering how to do it

[adriendelsalle]

@wolfv @beckermr I think this one is ready for reviews

[adriendelsalle]

I'll include a matrix test also to be sure it works as expected

[wolfv]

cool! looks good to me!

[AntoinePrv]

That's great! Thanks @adriendelsalle.

Would it make sens to make a release for this, or is there one planned soon?