"Could not run configuration in engine" when hot restarting on flutter_tester on Windows #21348
Description
On Windows, sending a Hot Restart (either via daemon, or just capital-R in the console runner) crashes with "Could not run configuration in engine".
PS M:\Coding\Applications\Google\flutter\examples\hello_world> flutter run -d flutter-tester
Running "flutter packages get" in hello_world... 2.9s
Launching lib/main.dart on Flutter test device in debug mode...
Syncing files to device Flutter test device... 3.9s
🔥 To hot reload changes while running, press "r". To hot restart (and rebuild state), press "R".
An Observatory debugger and profiler on Flutter test device is available at: http://127.0.0.1:63206/
For a more detailed help message, press "h". To quit, press "q".
Initializing hot reload...
Reloaded 0 of 293 libraries in 421ms.
Performing hot restart... /error: Unable to load .packages file 'M:\C:\Users\danny\AppData\Local\Temp\hello_worldd466747e-af4a-11e8-ac4e-001a7dda7113\hello_world\.packages'.
[ERROR:e:\b\build\slave\windows_engine\build\src\flutter\shell\common\engine.cc(158)] Could not prepare to run the isolate.
[ERROR:e:\b\build\slave\windows_engine\build\src\flutter\shell\common\engine.cc(117)] Engine not prepare and launch isolate.
Error -32000 received from application: Could not run configuration in engine.
JSON-RPC error -32000: Could not run configuration in engine.
package:json_rpc_2/src/client.dart 110:64 Client.sendRequest
package:json_rpc_2/src/peer.dart 68:15 Peer.sendRequest
package:flutter_tools/src/vmservice.dart 293:13 VMService._sendRequest
package:flutter_tools/src/vmservice.dart 842:12 VM.invokeRpcRaw
===== asynchronous gap ===========================
package:flutter_tools/src/vmservice.dart 865:49 VM.invokeRpc
===== asynchronous gap ===========================
package:flutter_tools/src/vmservice.dart 932:12 VM.runInView
package:flutter_tools/src/vmservice.dart 1439:20 FlutterView.runFromSource
===== asynchronous gap ===========================
package:flutter_tools/src/run_hot.dart 376:18 HotRunner._launchInView
===== asynchronous gap ===========================
package:flutter_tools/src/run_hot.dart 387:13 HotRunner._launchFromDevFS
===== asynchronous gap ===========================
package:flutter_tools/src/run_hot.dart 442:11 HotRunner._restartFromSources
===== asynchronous gap ===========================
package:flutter_tools/src/run_hot.dart 505:15 HotRunner.restart
===== asynchronous gap ===========================
package:flutter_tools/src/run_hot.dart 279:44 HotRunner.handleTerminalCommand
===== asynchronous gap ===========================
package:flutter_tools/src/resident_runner.dart 763:15 ResidentRunner.processTerminalInput
===== asynchronous gap ===========================
dart:async/zone.dart 1132:38 _rootRunUnary
dart:async/zone.dart 1029:19 _CustomZone.runUnary
dart:async/zone.dart 931:7 _CustomZone.runUnaryGuarded
dart:async/stream_impl.dart 336:11 _BufferingStreamSubscription._sendData
dart:async/stream_impl.dart 263:7 _BufferingStreamSubscription._add
dart:async/broadcast_stream_controller.dart 379:20 _SyncBroadcastStreamController._sendData
dart:async/broadcast_stream_controller.dart 254:5 _BroadcastStreamController.add
dart:async/broadcast_stream_controller.dart 480:11 _AsBroadcastStreamController.add
dart:async/zone.dart 1132:38 _rootRunUnary
dart:async/zone.dart 1029:19 _CustomZone.runUnary
dart:async/zone.dart 931:7 _CustomZone.runUnaryGuarded
dart:async/stream_impl.dart 336:11 _BufferingStreamSubscription._sendData
dart:async/stream_impl.dart 263:7 _BufferingStreamSubscription._add
dart:async/stream_transformers.dart 68:11 _SinkTransformerStreamSubscription._add
dart:async/stream_transformers.dart 15:11 _EventSinkWrapper.add
dart:convert/string_conversion.dart 268:11 _StringAdapterSink.add
dart:convert/string_conversion.dart 273:7 _StringAdapterSink.addSlice
dart:convert/string_conversion.dart 348:20 _Utf8ConversionSink.addSlice
dart:convert/ascii.dart 278:17 _ErrorHandlingAsciiDecoderSink.addSlice
dart:convert/ascii.dart 264:5 _ErrorHandlingAsciiDecoderSink.add
dart:convert/chunked_conversion.dart 86:18 _ConverterStreamEventSink.add
dart:async/stream_transformers.dart 120:24 _SinkTransformerStreamSubscription._handleData
dart:async/zone.dart 1132:38 _rootRunUnary
dart:async/zone.dart 1029:19 _CustomZone.runUnary
dart:async/zone.dart 931:7 _CustomZone.runUnaryGuarded
dart:async/stream_impl.dart 336:11 _BufferingStreamSubscription._sendData
dart:async/stream_impl.dart 263:7 _BufferingStreamSubscription._add
dart:async/stream_controller.dart 763:19 _SyncStreamController._sendData
dart:async/stream_controller.dart 639:7 _StreamController._add
dart:async/stream_controller.dart 585:5 _StreamController.add
dart:io/runtime/binsocket_patch.dart 1714:41 _Socket._onData
dart:async/zone.dart 1136:13 _rootRunUnary
dart:async/zone.dart 1029:19 _CustomZone.runUnary
dart:async/zone.dart 931:7 _CustomZone.runUnaryGuarded
dart:async/stream_impl.dart 336:11 _BufferingStreamSubscription._sendData
dart:async/stream_impl.dart 263:7 _BufferingStreamSubscription._add
dart:async/stream_controller.dart 763:19 _SyncStreamController._sendData
dart:async/stream_controller.dart 639:7 _StreamController._add
dart:async/stream_controller.dart 585:5 _StreamController.add
dart:io/runtime/binsocket_patch.dart 1276:33 new _RawSocket.<fn>
dart:io/runtime/binsocket_patch.dart 819:14 _NativeSocket.issueReadEvent.issue
dart:async/schedule_microtask.dart 41:21 _microtaskLoop
dart:async/schedule_microtask.dart 50:5 _startMicrotaskLoop
dart:isolate/runtime/libisolate_patch.dart 115:13 _runPendingImmediateCallback
dart:isolate/runtime/libisolate_patch.dart 172:5 _RawReceivePortImpl._handleMessage
Application finished.
PS M:\Coding\Applications\Google\flutter\examples\hello_world>
(cc @aam)