1 error: declaration of a nonstandard #[main] function may change over time, for now a top-level `fn main()` is required (see issue #29634)
2 --> $DIR/feature-gate-main.rs:12:1
4 12 | fn foo() {} //~ ERROR: declaration of a nonstandard #[main] function may change over time
7 = help: add #![feature(main)] to the crate attributes to enable
9 error: aborting due to previous error