Rename 'main' thread in Rust

I am working on an application that executes many processes, which at the same time use many threads. When something fails and the thread panics, rust outputs: thread 'main' panicked at 'explicit panic'. I would like to use this messages for debugging purposes, being able to identify the panicking process by its name, but in this case all processes have the 'main' thread name.

How can I change the main thread name?

I know I can change the name of a child thread using the std::thread::Builder, but this does not work for the current thread.

I have also tried using pthread_setname_np call (I am using a Linux system):

use libc::{pthread_self, pthread_setname_np};
use std::{ffi::CString, thread};

fn main() {

    // Set the name of the main thread
    let name = CString::new("new_name").unwrap();
    unsafe {
        pthread_setname_np(pthread_self(), name.as_ptr());
    }

    panic!();
}

Executing this with cargo run still panics with the main name.

I'm afraid this is impossible: the thread name is managed independently from the OS, and it is set only in two places in the standard library: when setting up main(), and when spawning a thread. There is no public API that changes it for the current thread (you can ask for one, if you believe this is important).

You can spawn a new thread and immediately join() it.

One way to put detail on which process crashed is to set up a custom panic handler. A good example of this is in the Deno runtime:

https://github.com/denoland/deno/pull/13145/files

Here's a short sample of how to do it:

fn main() {
    set_panic_hook(format!("Program {}", 1));
    panic!("something bad happened");
}

fn set_panic_hook(process_name: String) {
    let orig_hook = std::panic::take_hook();
    std::panic::set_hook(Box::new(move |panic_info| {
        eprintln!("\nPanic in process: {process_name}");
        orig_hook(panic_info);
        std::process::exit(1);
    }));
}

Rust Playground Example

Displays this output:

Panic in process: Program 1
thread 'main' panicked at 'something bad happened', src/main.rs:3:5