On Unix, read_secure_line first checks whether stdin is a TTY, and if not falls back to /dev/tty.

But when I tried

use std::error::Error;
use console::Term;

fn main() -> Result<(), Box<dyn Error>> {
    let term = Term::stdout();

    let x = term.read_secure_line()?;
    dbg!(x);
    Ok(())
}

with echo hello-world | target/debug/mytest
it hangs until I press return, after which it prints

Error: Os { code: 9, kind: Uncategorized, message: "Bad file descriptor" }

I don't think this should happen?

A bit of printf debugging revealed this line to be the source of the error

procfs reveals that the FD has been closed at that point.

and further debugging reveals that, indeed, someone is doing a little bit of FD closing.

this line moves out of f_tty, which closes the File.