Provide a way to select whether to use tox-conda on an env by env basis

[astrofrog]

It's currently possible to opt in of using tox-conda on a project by project basis, by specifying tox-conda in the requires section under [tox]. However, I would like to be able to control whether conda is used on an environment by environment basis, since I want to make sure that things work properly both with system Python and conda Python.

I think the cleanest way to do this might be to have a way to opt out of auto conda environment with a flag inside the [tox] section:

auto_use_conda = false

and then allow environments to specify:

use_conda = true

I'm happy to investigate how to code this up as a patch, but didn't want to waste time on it unless people think it would be a good idea to allow this? Just to be clear, the defaults would be as they are now, this would just be an opt-in mechanism to allow finer grained control. It would also allow projects to opt out of global enabling if a user has tox-conda installed but a project wants to guarantee conda is not used.

[saimn]

Related :
drdavella/tox-conda#11
drdavella/tox-conda#12

[AntoineD]

@gaborbernat will tox 4 support this kind of feature? (not limited to conda only)

[gaborbernat]

Yes 👍 see https://tox.readthedocs.io/en/rewrite/config.html#runner, which defaults to virtualenv but may be changed.

[abravalheri]

Hi guys, is there any example on how to use the runner option to achieve something similar to this?

I had a look on the docs, but I couldn't figure out what the value assigned to runner is...

(e.g.: is runner supposed to be the name of a CLI script that builds a virtual environment? An entry point that follows the same API as tox.tox_env.runner.RunToxEnv?)

[gaborbernat]

It's an entry point 🤞