initPrinter() hangs forever on Swift 2 Pro

[rekire]

When I call:

await iminPrinter.initPrinter();

The call never exits. I need to call it like this:

unawaited(
  _instance.iMinPrinter.initPrinter().then((result) {
    // this is never called on the Swift 2 Pro
    debugPrint('The printers init result is $result');
  }).onError((e, st) async {
    debugPrint('Error while initializing iMin printer support: $e\n$st');
  }),
);

In the logs I see this output:

D/NeoPrinterLibrary_PrinterHelper(13977): 绑定服务成功false

However printing works anyway.