error[E0658]: `#[start]` functions are experimental and their signature may change over time --> $DIR/feature-gate-start.rs:2:1 | LL | fn foo(_: isize, _: *const *const u8) -> isize { 0 } | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: see issue #29633 for more information = help: add `#![feature(start)]` to the crate attributes to enable = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0658`.