1 The entry point of the program was marked as `async`.
3 Erroneous code example:
6 async fn main() -> Result<(), ()> { // error!
11 `fn main()` or the specified start function is not allowed to be `async`. Not
12 having a correct async runtime library setup may cause this error. To fix it,
13 declare the entry point without `async`:
16 fn main() -> Result<(), ()> { // ok!