message: Ignore Signals Before Setting Initial Process Group
diff: @@ -50,6 +50,10 @@ fn main() {
  let _ = sys::signal(sys::SIGINT, handler);
  let _ = sys::signal(sys::SIGTERM, handler);
  + // This will block SIGTSTP, SIGTTOU, SIGTTIN, and SIGCHLD, which is required
  + // for this shell to manage its own process group / children / etc.
  + signals::block();
  +
  if let Ok(pid) = sys::getpid() {
  if sys::setpgid(0, pid).is_ok() {
  let _ = sys::tcsetpgrp(0, pid);
  