message: Fixes Windows build.
diff: @@ -158,7 +158,7 @@ struct Process::Private
  mutable std::optional<Process::ExitStatus> exitStatus {};
  std::optional<std::thread> exitWatcher;
  - Pty* pty = nullptr;
  + std::unique_ptr<Pty> pty {};
  PROCESS_INFORMATION processInfo {};
  STARTUPINFOEX startupInfo {};
  @@ -174,7 +174,7 @@ Process::Process(string const& _path,
  d(new Private {}, [](Private* p) { delete p; })
  {
  d->pty = move(_pty);
  - Require(static_cast<ConPty const*>(*d->pty));
  + Require(static_cast<ConPty const*>(d->pty.get()));
  initializeStartupInfoAttachedToPTY(d->startupInfo, static_cast<ConPty&>(*d->pty));
  