Incomplete console output when debugging MAUI app on iOS device

[thisisthekap]

Apple platform

iOS

Framework version

net8.0-*

Affected platform version

8.0.401

Description

After installing AppsFlyerXamarinBinding, no console output is shown when debugging on device, but shown in simulator.

Important notes:

• The same applies to other third party dependencies. Appsflyer is just an example to showcase the issue.
• The issue was reproduced using Visual Studio Code, but is reproducible as well using JetBrains Rider.
• Edit: This issue is present using several different iOS versions on devices (e.g. 17.6.1, 17.5, ...)

Steps to Reproduce

Repository with reproduction

https://github.com/thisisthekap/mauiiosloggingissue

Repro Steps

1. dotnet new maui
2. dotnet add package AppsFlyerXamarinBinding
3. Add that code to the simulator:

  public override bool FinishedLaunching(UIApplication application, NSDictionary launchOptions)
  {
	AppsFlyerLib.Shared.IsDebug = true;
	AppsFlyerLib.Shared.Start();

      return base.FinishedLaunching(application, launchOptions);
  }

4. Run on simulator
5. Output like [AppsFlyerSDK] [com.appsflyer.serial] [START] Initial start of the application is shown on the debug console
6. Run on device
7. No output like [AppsFlyerSDK] [com.appsflyer.serial] [START] Initial start of the application is shown on the debug console

Did you find any workaround?

No response

Relevant logs

No response

[thisisthekap]

A note on the severity of this issue: For us, having the full console output just on Simulator breaks MAUI development. We need to have reliable console output on devices, specifically iOS, in order to test device specific stuff such as IDFA constent and purchase related stuff.

[rolfbjarne]

This is due to the fact that last year (in iOS 17 / Xcode 15), Apple completely rewrote their libraries to interact with devices, and in the process didn't leave us any way to capture stdout/stderr from the process on device.

The good news is that they've fixed this for iOS 18 / Xcode 16, so once we've released .NET 9 (with support for iOS 18) this will work.

[thisisthekap]

@rolfbjarne Is there any way to backport this to the current stable?

[rolfbjarne]

@rolfbjarne Is there any way to backport this to the current stable?

No, because you also need to update to iOS 18 on your device and use Xcode 16.

You can view the output in the Console app though: https://support.apple.com/en-in/guide/console/cnsl1012/mac

[thisisthekap]

@rolfbjarne Thank you for your assistance!

[thisisthekap]

@rolfbjarne An additional finding: On initial deployment to a device, there seems to be no output at all (no loggers, no stdout, nothing in console). This makes me believe that this issue might be related to #21186

[rolfbjarne]

Closing since this will be fixed once we release Xcode 16 support.

In the end I discovered that it won't be necessary to upgrade any device, as long as you're using Xcode 16, it'll still work for devices with only iOS 17 installed.