- [x] FCP on closure capture changes: https://github.com/rust-lang/rust/issues/88126 - [x] FCP on reserved prefixes: https://github.com/rust-lang/rust/issues/88140 - [x] FCP on force-warn: https://github.com/rust-lang/rust/issues/86516#issuecomment-900382193 - [x] Decide that Rust 1.56 will ship Rust 2021 as stable: [Zulip thread](https://rust-lang.zulipchat.com/#narrow/stream/268952-edition-2021/topic/Release.20Decision/near/251224903) - [x] Make `--edition=2021` stable in rustc: https://github.com/rust-lang/rust/pull/88100 - [x] Remove/stabilize experimental 2021 cargo feature: https://github.com/rust-lang/cargo/pull/9800 - [x] Update `cargo` submodule: https://github.com/rust-lang/rust/pull/88563 - [x] Update edition guide and other documentation to reflect stability. - [x] Edition guide: https://github.com/rust-lang/edition-guide/pull/266 - [x] Update edition-guide submodule: https://github.com/rust-lang/rust/pull/88563 - [x] Check if there's any other documentation that needs updating
--edition=2021stable in rustc: Make Edition 2021 Stable #88100cargosubmodule: Update cargo, books #88563