• Implementation: Consider rust-version when selecting packages for cargo add #12078
• Unstable feature: -Zmsrv-policy

Problem

When running cargo add foo, we create a version-req out of the latest version in the index. If this has a higher rust-version, then that can break for people.

Proposed Solution

Constrain the candidate versions in the index by their rust-version being lesser or equal to the current crate's rust-version.

The main question is what to do when there are no matches due to rust-version.

• Add anyways
• Error with newest version's rust-version

Notes

No response