#### Note: this error code is no longer emitted by the compiler. More than one function was declared with the `#[main]` attribute. Erroneous code example: ```compile_fail #![feature(main)] #[main] fn foo() {} #[main] fn f() {} // error: multiple functions with a `#[main]` attribute ``` This error indicates that the compiler found multiple functions with the `#[main]` attribute. This is an error because there must be a unique entry point into a Rust program. Example: ```compile_fail #![feature(main)] #[main] fn f() {} // ok! ```