code: function kill(p, sig) {
    if (isWin) {
      let command = 'taskkill.exe';
      let args = ['/t', '/pid', p.pid];
      if (sig === 'SIGKILL') {
        args.push('/f');
      }
  
      execa(command, args).then(result => {
        // Processes without windows can't be killed without /F, detect and force
        // kill them directly
        if (result.stderr.indexOf('can only be terminated forcefully') !== -1) {
          kill(p, 'SIGKILL');
        }
      }).catch(err => {
        log.error(err);
      });
    } else {
      p.kill(sig);
    }
  }
docs: Kill process and all child processes cross platform