binary applications and exiting pipes behave badly together by default

[clux]

Consider an example program that produces a list to stdout, but takes some time doing so:

use std::{thread, time};

fn main() {
    let millis = time::Duration::from_millis(100);
    println!("a");
    thread::sleep(millis);
    println!("b");
    thread::sleep(millis);
    println!("c");
}

# works
./target/debug/piper | grep a
# crashes and shows me a rust backtrace
./target/debug/piper | grep -q a

The only related issue I found was #35108 which talks about using write! instead so you could handle the errors.

Sure enough, instead of println! using:

   let _ = io::stdout().write(b"a\n");

everywhere does fix it. But is this really a good substitute?

If we are writing CLI tools and are printing formatted strings to stdout we now have to start stuff like:

let _ = io::stdout().write(&format!("{}\n", svc).as_bytes());

which feels like a lot of faff for a "println that i don't care if the program i wrote into disappeared or not".

[sfackler]

Duplicate of #46016