Function failure

src/docker/docker.cpp:81–89

template <typename T>
static Future<T> failure(
    const string& cmd,
    int status,
    const string& err)
{
  return Failure(
      "Failed to run '" + cmd + "': " + WSTRINGIFY(status) +
      "; stderr='" + err + "'");
}


static Future<Nothing> _checkError(const string& cmd, const Subprocess& s)