error(path, e) {
    let status;
    let stdout;

    if (e.code === 'ENOENT' && e.syscall === 'scandir') {
      status = 1;
      stdout = `ls: cannot access ${path}: No such file or directory`;
    } else {
      status = 2;
      stdout = e.stack;
    }

    ls.self.log(stdout);
    return {status, stdout};
  }
Returns ls stderr and response codes
for errors.

@param {String} path
@param {Error} e
@param {String} e.code
@param {String} e.syscall
@param {String} e.stack
@api private