OS is Ubuntu 20.04

cat /etc/os-release
NAME="Ubuntu"
VERSION="20.04 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04 LTS"
VERSION_ID="20.04"

Each time when inputing something in CLI, I got a msg "WARN RS - rustyline:718 - cannot read initial cursor location".

$ deno
Deno 1.1.3
exit using ctrl+d or close()
WARN RS - rustyline:718 - cannot read initial cursor location
> "hello"
hello
WARN RS - rustyline:718 - cannot read initial cursor location
> "world"
world
WARN RS - rustyline:718 - cannot read initial cursor location
>

Source code for that warning:

From "https://github.com/kkawakam/rustyline/blob/master/src/tty/unix.rs"

    fn move_cursor_at_leftmost(&mut self, rdr: &mut PosixRawReader) -> Result<()> {
        if rdr.poll(0)? != 0 {
            debug!(target: "rustyline", "cannot request cursor location");
            return Ok(());
        }
        /* Report cursor location */
        self.write_and_flush(b"\x1b[6n")?;
        /* Read the response: ESC [ rows ; cols R */
        if rdr.poll(100)? == 0
            || rdr.next_char()? != '\x1b'
            || rdr.next_char()? != '['
            || read_digits_until(rdr, ';')?.is_none()
        {
            warn!(target: "rustyline", "cannot read initial cursor location");
            return Ok(());
        }
        let col = read_digits_until(rdr, 'R')?;
        debug!(target: "rustyline", "initial cursor location: {:?}", col);
        if col.is_some() && col != Some(1) {
            self.write_and_flush(b"\n")?;
        }
        Ok(())
    }

Don't know how this comes up but I always get that warning on my own server. OS was upgraded from 18.04 to 20.04 online.
However, on another machine with newly installed Ubuntu 20.04, this problem nerver happens. Can't reproduce it on the second machine.

Not familiar with Rust, what I want to know is:

• 1. Possible causes of that warning "WARN RS - rustyline:718 - cannot read initial cursor location".
• 2. How could I solve that?

Thanks for any useful help! :D