Use Honest Minimum Dependencies

RUST-USE-HONEST-MINIMUM-DEPENDENCIES

Summary

Set dependency requirements to the lowest compatible versions the crate actually supports. Raise minimums only for required APIs, fixes, features, security needs, or MSRV interactions.

Rule

Use the lowest honest compatible dependency requirement.

Why

The manifest should state the lowest compatible dependency versions the crate honestly supports. Overstating minimums reduces downstream flexibility; understating them breaks minimal-version builds when newer APIs are used.

Helps

Helps downstream users with older compatible dependency graphs build the crate without unnecessary version pressure.

Limits

Raise the minimum when a newer API, behavior fix, security patch, feature, or MSRV interaction is actually required.

Agent Instruction

Use the lowest honest compatible dependency requirement because the manifest should state the lowest
compatible dependency versions the crate honestly supports.

Mechanisms

Set the manifest requirement to the lowest version that provides the APIs used, run minimal-version checks where practical, and keep routine updates in the lockfile.

References