Function macroquad::window::set_panic_handler

pub fn set_panic_handler<T, F>(future: F) where
    T: Future<Output = ()> + 'static,
    F: Fn(String, String) -> T + Send + Sync + 'static, 

With set_panic_handler set to a handler code, macroquad will use std::panic::catch_unwind on user code to catch some panics.

Sometimes it is nice to let player send a bug report with a screenshot of an error. It is way easier to ask for a screenshot than ask to connect to a phone with adb and post a log.

For this very case “set_panic_handler” exists.

set_panic_handler(|msg, backtrace| async move {
    loop {
        clear_background(RED);
        ui::root_ui().label(None, &msg);
        for line in backtrace.split('\n') {
            root_ui().label(None, line);
        }
        next_frame().await;
     }
});

set_panic_handler acts as a second app entry-point, that will be used after a panic in user code will happen. Macroquad will also try to catch some OS panics, but not all of them - some compatibility bugs may end up crashing the app.

Withot set_panic_handler macroquad will not use catch_unwind at all, therefore panic_handler is completely optional. NOTE: only with “backtrace” macroquad feature backtrace string will contain an actual backtrace. Otherwise only panic location and message will be available. NOTE: on android, even with “backtrace” nice backtrace is available only if the game is compiled with sdk >= 21. To use sdk >= 21 add “min_sdk_version = 21” to Cargo.toml