message: Prevent output flags from overwriting existing files
diff: //! File I/O helpers for CLI binaries.
  -use std::fs::File;
  +use std::fs::{File, OpenOptions};
  use std::io::{self, Read, Write};
  const SHORT_OUTPUT_LENGTH: usize = 20 * 80;
  @@ -117,7 +117,12 @@ impl OutputWriter {
  pub fn new(output: Option<String>, deny_tty: bool) -> io::Result<Self> {
  let is_tty = console::user_attended();
  if let Some(filename) = output {
  - Ok(OutputWriter::File(File::create(filename)?))
  + Ok(OutputWriter::File(
  + OpenOptions::new()
  + .write(true)
  + .create_new(true)
  + .open(filename)?,
  + ))
  } else if is_tty && deny_tty {
  Err(io::Error::new(
  io::ErrorKind::Other,
  