-`fn main()` or the specified start function is not allowed to be
-async. You might be seeing this error because your async runtime
-library is not set up correctly.
+The entry point of the program was marked as `async`.
Erroneous code example:
```compile_fail,E0752
-async fn main() -> Result<i32, ()> {
- Ok(1)
+async fn main() -> Result<(), ()> { // error!
+ Ok(())
+}
+```
+
+`fn main()` or the specified start function is not allowed to be `async`. Not
+having a correct async runtime library setup may cause this error. To fix it,
+declare the entry point without `async`:
+
+```
+fn main() -> Result<(), ()> { // ok!
+ Ok(())
}
```