Get Panic Message

main.rs

// Used to get the panic message after PR 115974 was merged, which changed the type passed through
// in the "info" parameter in the "std::panic::set_hook" callback/delegate. In the new type that
// is passed through, the "message" field was removed. To get the message back from the panic info,
// use the "payload_message" function.

use std::panic::PanicHookInfo;

fn main() {
    std::panic::set_hook(Box::new(move |info| {
        println!("Panic Info: {:#?}", info);
        println!("{:#?}", payload_message(info));
    }));
    panic!("Lorem Ipsum");
}

fn payload_message(info: &PanicHookInfo) -> String {
    if let Some(s) = info.payload().downcast_ref::<&str>() {
        String::from(*s)
    } else if let Some(s) = info.payload().downcast_ref::<String>() {
        s.clone()
    } else {
        String::from("<unknown error> (unhandled downcast_ref in payload_message)")
    }
}