the trait bound is not satisfied

[Aworldc]

Got this error message. Spent 2 hours debugging. Can't figure out what is wrong:

the trait bound [closure@src\app.rs:17:19: 17:21]: Handler<_, _, _> is not satisfied.

main.rs

use serde_json as json;
use std::env;
use std::fs;

mod app;
mod config;

#[tokio::main]
async fn main() {
    println!("MacroPanel v0.1.0");

    let args: Vec<String> = env::args().collect();
    if args.len() == 1 {
        println!("No config file provided");
        println!("Usage: macropanel <path_to_config_file>");
    } else {
        let data = fs::read_to_string(args.get(1).unwrap()).expect("Failed to read config file");
        println!("Successfully read config file");

        let config_file: config::MacroPanelConfigFile =
            json::from_str::<config::MacroPanelConfigFile>(&data)
                .expect("Failed to decode config file");

        println!("Successfully decoded config file");
        println!("");
        app::main(config_file).await;
    }
}

config.rs

use serde::{Deserialize, Serialize};

#[derive(Serialize, Deserialize, Clone)]
pub struct MacroPanelAction {
    pub name: String,
}

#[derive(Serialize, Deserialize, Clone)]
pub struct MacroPanelConfigFile {
    pub actions: Vec<MacroPanelAction>,
}

app.rs

use crate::config::MacroPanelConfigFile;
use axum::{
    body::Body,
    handler::{self, Handler},
    routing::get,
    Router,
};
use std::net::SocketAddr;

pub async fn main(config: MacroPanelConfigFile) {
    let config_str: String = serde_json::to_string(&config).unwrap();

    async fn root() -> &'static str {
        "Hello, World!"
    }

    let handler = || async move { return config };

    let app: axum::routing::Router = Router::new()
        .route("/", get(root))
        .route("/actions", get(handler));

    let addr = SocketAddr::from(([0, 0, 0, 0], 3000));

    println!("Listening at {}", addr);

    axum::Server::bind(&addr)
        .serve(app.into_make_service())
        .await
        .unwrap();
}

Please help.

[Aworldc]

Last night while i was in bed i thought of a way to fix this:
I rewrote handler from the above app.rs so it read from a file, instead of trying to use an external variable, which i thought was the issue. It worked.