1The entry point of the program was marked as `async`.23Erroneous code example:45```compile_fail,E07526async fn main() -> Result<(), ()> { // error!7    Ok(())8}9```1011`fn main()` or the specified start function is not allowed to be `async`. Not12having a correct async runtime library setup may cause this error. To fix it,13declare the entry point without `async`:1415```16fn main() -> Result<(), ()> { // ok!17    Ok(())18}19```