mlaunch: Retrieving device logs via `--logdev` in Xharness not working on iOS 18 queue

[matouskozak]

Using new mlaunch (version 1.1.11) inside Xharness leads to failure:

[01:23:08.6266650] /private/tmp/helix/working/B64E09AC/p/microsoft.dotnet.xharness.cli/10.0.0-dev/tools/net8.0/any/../../../runtimes/any/native/mlaunch/bin/mlaunch --sdkroot /Applications/Xcode_16.1.app --logdev --devname Dncengosx162
[01:23:09.5567310] error MT0000: Unexpected error - Please file a bug report at https://github.com/xamarin/xamarin-macios/issues/new
[01:23:09.5582790] System.InvalidCastException: Unable to cast object of type 'Xamarin.Hosting.DeviceCtlDevice' to type 'Xamarin.Hosting.RealDevice'.
[01:23:09.5582830]    at Xamarin.Hosting.Logger.LogAsync(String, TextWriter) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Hosting/Logger.cs:line 152
[01:23:09.5582840]    at Xamarin.Hosting.Logger.LogToConsoleAsync(String) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Hosting/Logger.cs:line 172
[01:23:09.5582850]    at Xamarin.Hosting.Logger.<>c__DisplayClass5_0.<<LogToConsole>b__0>d.MoveNext() in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Hosting/Logger.cs:line 179
[01:23:09.5582850] --- End of stack trace from previous location ---
[01:23:09.5582860]    at System.Threading.Tasks.Task.<>c.<ThrowAsync>b__128_0(Object state)
[01:23:09.5582870]    at Foundation.NSAsyncSynchronizationContextDispatcher.Apply() in /Users/builder/azdo/_work/1/s/xamarin-macios/src/Foundation/NSAction.cs:line 176
[01:23:09.5582880]    at InvokeStub_NSAsyncSynchronizationContextDispatcher.Apply(Object, Object, IntPtr*)
[01:23:09.5583020]    at System.Reflection.MethodBaseInvoker.InvokeWithNoArgs(Object, BindingFlags)
[01:23:09.5583030] --- End of stack trace from previous location ---
[01:23:09.5583040]    at ObjCRuntime.Runtime.InvokeMethod(MethodBase, Object, IntPtr) in /Users/builder/azdo/_work/1/s/xamarin-macios/src/ObjCRuntime/Runtime.CoreCLR.cs:line 777
[01:23:09.5583050]    at ObjCRuntime.Runtime.InvokeMethod(MonoObject*, MonoObject*, IntPtr) in /Users/builder/azdo/_work/1/s/xamarin-macios/src/ObjCRuntime/Runtime.CoreCLR.cs:line 667
[01:23:09.5583050]    at ObjCRuntime.Runtime.bridge_runtime_invoke_method(MonoObject* method, MonoObject* instance, IntPtr parameters, IntPtr* exception_gchandle) in /Users/builder/azdo/_work/1/s/xamarin-macios/runtime/Delegates.generated.cs:line 1296
[01:23:09.5583060]    at ObjCRuntime.Messaging.void_objc_msgSend_NativeHandle(IntPtr, IntPtr, NativeHandle)
[01:23:09.5583070]    at Foundation.NSRunLoop.RunUntil(NSDate) in /Users/builder/azdo/_work/1/s/xamarin-macios/src/build/dotnet/macos/generated-sources/Foundation/NSRunLoop.g.cs:line 225
[01:23:09.5583210]    at Xamarin.Utils.NSRunLoopExtensions.RunUntilEvent(NSRunLoop, ManualResetEvent, Nullable`1 ) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Utils/Extensions.cs:line 16
[01:23:09.5583220]    at Xamarin.Hosting.Services.RunMainLoopUntil(ManualResetEvent) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Hosting/Services.cs:line 1750
[01:23:09.5583220]    at Xamarin.Hosting.Logger.LogToConsole(String) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Hosting/Logger.cs:line 182
[01:23:09.5583230]    at Xamarin.Launcher.DevController.ShowLog(String) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Launcher/controller-device.cs:line 46
[01:23:09.5583270]    at Xamarin.Launcher.Driver.MainAsync() in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Launcher/Main.cs:line 452
[01:23:09.5583280]    at Xamarin.Utils.NSRunLoopExtensions.RunUntilTaskCompletion[T](NSRunLoop, Task`1) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Utils/Extensions.cs:line 29
[01:23:09.5583280]    at Xamarin.Launcher.Driver.Main2(String[]) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Launcher/Main.cs:line 441
[01:23:09.5583320]    at Xamarin.Launcher.Driver.Main(String[]) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Launcher/Main.cs:line 128
[01:23:09.5644180] 

The same Xharness code used to retrieve the device log:
https://github.com/dotnet/xharness/blob/4d96da724de267c2fe804b2c973f0047b00237ea/src/Microsoft.DotNet.XHarness.iOS.Shared/Execution/Arguments.cs#L43-L48

works well on older iPhone queue running with iOS 15.4.

Per offline discussion with Rolf, retrieving device logs via --logdev doesn't work on iOS 17+. A possible workaround might be using log collect --device-udid <UDID> with the disadvantage that it requires elevated privileges.

---

fyi: @rolfbjarne @vitek-karas @ivanpovazan

[matouskozak]

I investigated a bit and I'm unsure whether --logdev is the culprint.

I tried not using --logdev and see what happens... mlaunch --sdkroot /Applications/Xcode_16.1.app --devname Dncengosx160 and it still crashes with

​[05:58:00] dbug: error MT1033: Could not uninstall the application 'net.dot.iOS.Simulator.PInvoke.Test' from the device ' '00008030-000325E43423402E'': Unable to cast object of type 'Xamarin.Hosting.DeviceCtlDevice' to type 'Xamarin.Hosting.RealDevice'.
[05:58:00] dbug: 
[05:58:00] dbug: --- inner exception
[05:58:00] dbug: System.InvalidCastException: Unable to cast object of type 'Xamarin.Hosting.DeviceCtlDevice' to type 'Xamarin.Hosting.RealDevice'.
[05:58:00] dbug: at Xamarin.Hosting.DeviceDiscovery.FindDeviceWithAMDeviceAsync(String, Boolean , Boolean ) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Hosting/DeviceDiscovery.cs:line 89
[05:58:00] dbug: at Xamarin.Launcher.DevController.UninstallApplicationAsync(String, String, String) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Launcher/controller-device.cs:line 59
[05:58:00] dbug: ---
[05:58:00] dbug: at Xamarin.Launcher.DevController.UninstallApplicationAsync(String, String, String) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Launcher/controller-device.cs:line 67
[05:58:00] dbug: at Xamarin.Launcher.Driver.MainAsync() in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Launcher/Main.cs:line 458
[05:58:00] dbug: at Xamarin.Utils.NSRunLoopExtensions.RunUntilTaskCompletion[T](NSRunLoop, Task`1) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Utils/Extensions.cs:line 29
[05:58:00] dbug: at Xamarin.Launcher.Driver.Main2(String[]) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Launcher/Main.cs:line 441
[05:58:00] dbug: at Xamarin.Launcher.Driver.Main(String[]) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Launcher/Main.cs:line 128
[05:58:00] dbug: Process mlaunch exited with 1

It is not the same crash as with mlaunch --sdkroot /Applications/Xcode_16.1.app --logdev --devname Dncengosx160 though.

[rolfbjarne]

That's just another issue (very similar though)

[rolfbjarne]

I investigated a bit and I'm unsure whether --logdev is the culprint.

I tried not using --logdev and see what happens... mlaunch --sdkroot /Applications/Xcode_16.1.app --devname Dncengosx160 and it still crashes with

​[05:58:00] dbug: error MT1033: Could not uninstall the application 'net.dot.iOS.Simulator.PInvoke.Test' from the device ' '00008030-000325E43423402E'': Unable to cast object of type 'Xamarin.Hosting.DeviceCtlDevice' to type 'Xamarin.Hosting.RealDevice'.
[05:58:00] dbug: 
[05:58:00] dbug: --- inner exception
[05:58:00] dbug: System.InvalidCastException: Unable to cast object of type 'Xamarin.Hosting.DeviceCtlDevice' to type 'Xamarin.Hosting.RealDevice'.
[05:58:00] dbug: at Xamarin.Hosting.DeviceDiscovery.FindDeviceWithAMDeviceAsync(String, Boolean , Boolean ) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Hosting/DeviceDiscovery.cs:line 89
[05:58:00] dbug: at Xamarin.Launcher.DevController.UninstallApplicationAsync(String, String, String) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Launcher/controller-device.cs:line 59
[05:58:00] dbug: ---
[05:58:00] dbug: at Xamarin.Launcher.DevController.UninstallApplicationAsync(String, String, String) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Launcher/controller-device.cs:line 67
[05:58:00] dbug: at Xamarin.Launcher.Driver.MainAsync() in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Launcher/Main.cs:line 458
[05:58:00] dbug: at Xamarin.Utils.NSRunLoopExtensions.RunUntilTaskCompletion[T](NSRunLoop, Task`1) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Utils/Extensions.cs:line 29
[05:58:00] dbug: at Xamarin.Launcher.Driver.Main2(String[]) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Launcher/Main.cs:line 441
[05:58:00] dbug: at Xamarin.Launcher.Driver.Main(String[]) in /Users/builder/azdo/_work/9/s/src/Xamarin.Hosting/Xamarin.Launcher/Main.cs:line 128
[05:58:00] dbug: Process mlaunch exited with 1

It is not the same crash as with mlaunch --sdkroot /Applications/Xcode_16.1.app --logdev --devname Dncengosx160 though.

I've fixed this problem (https://dev.azure.com/devdiv/DevDiv/_git/macios-mlaunch/pullrequest/620893), but the original issue here (--logdev) is a bit harder.

This is Apple's supported way of getting the device log:

$ sudo log collect --device-udid ...

And there are main issues here:

1. It requires sudo. mlaunch shouldn't be launched with sudo, and having mlaunch use sudo doesn't feel right either.
2. The existing mlaunch --logdev works in a streaming fashion, where it connects to the device and prints any device log output as it's written there. log collect is supposed to be executed after the fact, and it collects the last X amount of logs from the device. There's no good way to have mlaunch --logdev hide this difference, because you'd have to somehow tell mlaunch when you want the log (for instance at the end of a test run), and what you actually do right now is to terminate mlaunch (because you've reached the end of the test run, and presumably already the logs you were interested in have been streamed to you).

One idea is to introduce another command (say mlaunch --logdev2) that could work for both scenarios, but that doesn't fix the sudo problem. Also one reason for mlaunch --logdev to exist was that at the time there was no supported way from Apple to retrieve the device log from the command line, and now there is.

So I think the best option here is to change mlaunch to show a better error message ("use sudo log stream instead).

[rolfbjarne]

Closing; a better error message has been implemented (https://devdiv.visualstudio.com/DevDiv/_git/macios-mlaunch/pullrequest/622502).