message: Print all errors
diff: -use super::super::{Capture, Function, FunctionError, Shell};
  +use super::super::{Capture, Function, Shell};
  use std::process;
  use sys;
  @@ -10,8 +10,8 @@ pub(crate) fn command_not_found(shell: &mut Shell, command: &str) -> bool {
  if let Err(err) = shell.fork(Capture::None, |child| {
  let result = unsafe { function.read() }.execute(child, &["ion", command]);
  - if let Err(FunctionError::InvalidArgumentCount) = result {
  - eprintln!("ion: COMMAND_NOT_FOUND function takes an invalid number of arguments: must be exactly one");
  + if let Err(err) = result {
  + eprintln!("ion: COMMAND_NOT_FOUND function call: {}", err);
  }
  }) {
  eprintln!("ion: fork error: {}", err);
  