rough outline of a "conda develop" using pypa/build

[dholth]

Description

This is how to create and install an editable wheel with pypa/build, as a replacement for "conda develop". At each step we have the opportunity to install dependencies using our preferred installer instead of pip.

#4251

Checklist - did you ...

• Add a file to the news directory (using the template) for the next release's release notes?
• Add / update necessary tests?
• Add / update outdated documentation?

[dholth]

This is what pypa/build's cli does to build an ordinary wheel in its own environment, providing pip or uv as the available installers. We could add a conda installer.

def _build_in_isolated_env(
    srcdir: StrPath,
    outdir: StrPath,
    distribution: Distribution,
    config_settings: ConfigSettings | None,
    installer: _env.Installer,
) -> str:
    with DefaultIsolatedEnv(installer=installer) as env:
        builder = ProjectBuilder.from_isolated_env(env, srcdir)
        # first install the build dependencies
        env.install(builder.build_system_requires)
        # then get the extra required dependencies from the backend (which was installed in the call above :P)
        env.install(builder.get_requires_for_build(distribution, config_settings or {}))
        return builder.build(distribution, outdir, config_settings or {})

[dholth]

Ask them to use conda uninstall or pip uninstall since these are installed like standard Python packages

[dholth]

Could we convert the ephemeral wheel into a conda package and install that instead? Or would it be too much trouble to avoid keeping that in conda's package cache?