error: expected `async`
 --> tests/invalid/not_async.rs:5:5
  |
5 | pub fn not_async() -> Result<String, ServerFnError> {
  |     ^^

warning: unused import: `server_fn::error::ServerFnError`
 --> tests/invalid/not_async.rs:2:5
  |
2 | use server_fn::error::ServerFnError;
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: `#[warn(unused_imports)]` on by default
