'deps-only' mode for 'hatch env create'?

[kpfleming]

For a new project I'm setting up, I build a container image with four Python versions in it, and six Hatch environments pre-built with the project's dependencies (both the core dependencies and the linters/testing tools). When my CI jobs runs, they can launch a container from this image and immediately run the actual tasks to be done, after installing the project from the source directory, without having to wait for package installation and other stuff. This makes the lint and CI jobs run faster, and also avoids randomly getting new versions of dependencies when they aren't expected.

In order to make this work I had to inject detached=true into my CI environments, so that Hatch wouldn't attempt to install the project into them (during the pre-creation process the project source code isn't even visible to Hatch, only the pyproject.toml file). While this works, it's not elegant :-)

Would others be interested in something like hatch env create foo --deps-only, which would run the normal environment-creation process for foo but not attempt to build and install the project into it?

[ofek]

https://hatch.pypa.io/latest/config/environment/overview/#skip-install

[kpfleming]

Will give this a try, I tried a conditional thing before and couldn't figure out how to make it work :-)

[kpfleming]

This works perfectly. Thanks.

[ofek]

Awesome, happy to help!

[kpfleming]

Sorry, I spoke too soon :-(

'skip-install' means the project is not installed, which means its dependencies aren't installed either. Basically I want to install all of the dependencies but not the project, although I think I'll be OK with installing the project at this point since it will be overridden later when that same image is used with a newer checkout from the repository.

[kpfleming]

OK, for completeness, this is what I'm doing now. Assume the project is named 'foo' and the environment in question is named 'lint':

1. During creation of the container image, run hatch env create lint.
2. After that, run hatch run lint:pip uninstall --yes foo.

This leaves the environment in the image prepared with all of foo's dependencies, but without foo installed.

Next, during CI:

1. Run hatch build -t wheel to build a wheel.
2. Run hatch run lint:pip install dist/*.whl to install the package into the environment.

The result of this is that the CI process is quite fast, as there's no need to download and install all of the dependency packages.