pranaless

Yes and no. While coreutils does provide an echo binary, shells also have a built-in for optimisation purposes.

At first I had the code calling the binary directly, but then changed it to spawning a shell (and so using the builtin). It’s very cursed either way.

use std::process::Command;

fn main() {
    Command::new("sh")
        .arg("-c")
        .arg("echo Hello World!")
        .spawn()
        .unwrap();
}

Like this?

Try builtins.deepSeq: something like builtins.trace (builtins.deepSeq some-list some-list) false

According to the manual, it evaluates its first argument deeply and returns the second.