Async/await error does not have line information

[swilcox3]

I was porting over my actix-web server to 2.0.0 and async-await and ran into this error while rewriting a test.

The code:

#[actix_rt::test]
async fn test_get_all_files() {
    let test_db = test_setup("test_get_all_files", "test_files", "");
    let mut app = test::init_service(
        App::new()
            .data(ServerGlobals::new_test(&test_db.db))
            .service(web::resource("/get-all-files").to(get_files_and_folders)),
    )
    .await;
    let resp = call_request!(app, "/get-all-files");
    assert_eq!(resp.status(), http::StatusCode::OK);
    let body = test::read_body(resp);
    let paths: Vec<ps_database::DirEntry> = serde_json::from_slice(&body).unwrap();

    let mut answers = std::collections::HashSet::new();
    answers.insert(PathBuf::from("test_files/"));
    answers.insert(PathBuf::from("test_files/write_file"));
    answers.insert(PathBuf::from("test_files/test_original.vwxp"));
    answers.insert(PathBuf::from("test_files/write_file/test_write_file.vwxp"));
    for dir in paths {
        dir.iterate_paths(&mut |path| {
            assert!(path.is_dir() || path.extension().unwrap() == "vwxp");
            answers.remove(path);
        });
    }
    assert_eq!(answers.len(), 0);
}

I received this error message:

error[E0308]: mismatched types
  |
  = note: expected type `&[u8]`
             found type `&impl futures::Future`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0308`.

This bug is not about the error itself, I figured out what the error is. test::read_body(resp) needs a .await after it. The issue is that the error had no line information included, so I had to go commenting out sections of code to find out which test had the error. My VSCode showed the red squiggly on the very first character of my main.rs.

[jonas-schievink]

Presumably a duplicate of #68430, so closing in favor of that