1error[E0658]: the `#[register_tool]` attribute is an experimental feature 2 --> $DIR/feature-gate-register_tool.rs:1:1 3 | 4LL | #![register_tool(tool)] 5 | ^^^^^^^^^^^^^^^^^^^^^^^ 6 | 7 = note: see issue #66079 <https://github.com/rust-lang/rust/issues/66079> for more information 8 = help: add `#![feature(register_tool)]` to the crate attributes to enable 9 10error: aborting due to previous error 11 12For more information about this error, try `rustc --explain E0658`. 13