vendors/execa.js/getSpawnedResult
var getSpawnedResult = async ({ stdout, stderr, all }, { encoding, buffer, maxBuffer }, processDone) => {
  const stdoutPromise = getStreamPromise(stdout, { encoding, buffer, maxBuffer });
  const stderrPromise = getStreamPromise(stderr, { encoding, buffer, maxBuffer });
  const allPromise = getStreamPromise(all, { encoding, buffer, maxBuffer: maxBuffer * 2 });
  try {
    return await Promise.all([processDone, stdoutPromise, stderrPromise, allPromise]);
  } catch (error) {
    return Promise.all([
      { error, signal: error.signal, timedOut: error.timedOut },
      getBufferedData(stdout, stdoutPromise),
      getBufferedData(stderr, stderrPromise),
      getBufferedData(all, allPromise)
    ]);
  }
};