Add $HFPR_VERSION substitution

[hynek]

This allows to include the package version in the PyPI readme.

Does this make sense @ofek?

[ofek]

Makes sense, however since this isn't an environment variable where we would have to be cognizant of conflicts, why not $PROJECT_VERSION?

[ofek]

Actually right the readme may for some reason contain that string, so this name is fine

[hynek]

Cool, thanks!

[henryiii]

Would it be possible to give this a default? Scikit-build-core is using this so adding a new required argument broke the plugin. Ideally we should finish dynamic-metadata and then support that directly instead of wrapping it. I can work around it, just would have been nice.

[henryiii]

FYI, the dynamic-metadata spec currently doesn't have a way to access other metadata values. I wonder if it would be worth trying? It would also be important to make sure version was computed before the other values - in fact, I think it only makes sense for other plugins to be able to see the version, since otherwise you'd need to declare dependencies and topologically sort.

[ofek]

• I think this change is okay because I view the only guaranteed interface to be through config (user facing). I would never assume that folks would use the internal logic of plugins.
• You are correct that version is important which is why if there are hooks that the version (if dynamic) is computed first https://github.com/pypa/hatch/blob/hatchling-v1.21.0/backend/src/hatchling/metadata/core.py#L167-L171

[hynek]

Aw sorry you need a default for build_text? I can do a 24.1 tomorrow when I’m sober again.