internals.rust-lang.org/t/attempting-to-clean-up-the-feature-activation-syntax/24718 Attempting to clean up the feature activation syntax?
A Cargo maintainer examines the confusing overlap of feature activation forms like foo/bar, dep:foo and foo?/bar, and proposes a phased cleanup: deprecate foo/bar in manifests, change CLI semantics under a new resolver, and possibly reintroduce foo/bar later. Downsides noted include Cargo.lock bloat and index syntax concerns.
— via Rust Internals, epage