Set the `CARGO_PKG_README` environment variable

[nagisa]

Problem

Cargo may rewrite the package’s Cargo.toml and move the README file around, relative to the manifest. I would like to include_str!() this README in my lib.rs, but am unable to do so right now, because if I specify include_str!("../../README") it works for development, but I can’t package my crate. Conversely if I specify include_str!("../README") it works when packaged, but not during development.

Proposed Solution

Having an environment variable that would tell me where to find the README file would probably be the most straightforward option.

Notes

No response

[weihanglo]

To me, it seems fine to add a new environment variable. You could follow how other environments were added. Basically you will

• Set a new environment variable here
• Add an explanation here for the new variable.
• Assert the new variable has been set in this test.
• Submit a pull request with a explanation why this is useful with a clear use case.

The Cargo team would probably do an FCP for that before merging.

[chansuke]

@rustbot claim