Rust errors / Everything else
Rust compiler error · checked with rustc 1.99.0
Rust error E0752: `main` function is not allowed to be `async`
What it meansThe entry point of the program was marked as async.
What rustc prints
error[E0752]: `main` function is not allowed to be `async`
--> main.rs:1:1
|
1 | async fn main() -> Result<(), ()> { // error!
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `main` function is not allowed to be `async`Real output of rustc 1.99.0 compiling the official example below (2021 edition). Your names and line numbers will differ; the first line is the part to match.
E0752Everything else
Activein rustc 1.99.0
7related errors linked below
The compiler team's explanation
The entry point of the program was marked as async.
Erroneous code example:
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(())
}From rustc --explain E0752 (1.99.0), part of the Rust project, MIT or Apache-2.0. Official page.
Related errors
- E0061this function takes N arguments but M were supplied
- E0412cannot find type in this scope
- E0515cannot return reference to local variable
- E0728await is only allowed inside async functions and blocks
- E0733recursion in an async fn requires boxing
- E0753expected outer doc comment
- E0758unterminated block comment
Up next
Often hit nextE0061: this function takes N arguments but M were suppliedA related error from the same family.Read it next →Did this answer your question?