Release crash on unmanagedcallersonly framework code

[333fred]

Android application type

Android for .NET (net6.0-android, etc.)

Affected platform version

VS 17.6p1/.NET 8p1

Description

I have a maui app (closed source, unfortunately, but my alias is frsilb if the logs I've attached aren't enough and we need to do more debugging) that uses both EF Core and SignalR. I'm getting a crash in release mode:

Assertion at /__w/1/s/src/mono/mono/metadata/icall.c:6175, condition `!only_unmanaged_callers_only' not met

The crash doesn't happen on every build of the app, but when it does happen, it happens on every launch of that build, and it seems to happen more often than not. I've been unable to minimize it to a single cause yet. No crash occurs when running in debug mode.

Steps to Reproduce

I've attached the logs, let me know if they're not enough to figure it out and we can debug my app. I haven't been able to minimize the crash.

Did you find any workaround?

None.

Relevant log output

Here's the logs with the backtrace.

[333fred]

/cc @MichalPetryka

[MichalPetryka]

/cc @MichalPetryka

The backtrace seems to suggest that either of:
https://github.com/xamarin/xamarin-android/blob/928e7b97f81b3fcaa4655dbc4b8a2f5667e5d38b/src/Mono.Android/Android.Runtime/JNIEnvInit.cs#L54-L57
https://github.com/xamarin/xamarin-android/blob/928e7b97f81b3fcaa4655dbc4b8a2f5667e5d38b/src/Mono.Android/Android.Runtime/JNIEnvInit.cs#L78-L81

is missing UnmanagedCallersOnly in runtime here:
https://github.com/xamarin/xamarin-android/blob/928e7b97f81b3fcaa4655dbc4b8a2f5667e5d38b/src/monodroid/jni/monodroid-glue.cc#L1100
or here:
https://github.com/xamarin/xamarin-android/blob/928e7b97f81b3fcaa4655dbc4b8a2f5667e5d38b/src/monodroid/jni/monodroid-glue.cc#L1123

which hints that something causes C# DLLs built for .Net Framework to be used with .Net
8p1 runtime.

[grendello]

@333fred @MichalPetryka my first suspicion is, indeed, that there's a mix-up in the packaged assemblies. It is usually caused by something in the obj/ folder getting messed up. Unfortunately, it's impossible to say what's the problem from a runtime crash. We will need a binlog of a build that crashes - please start building with -bl passed to dotnet build (or its equivalent setting in the IDE) and attach the problematic build's one here, once the crash happens. Another thought I had about it is whether your project uses any Android libraries that target classic XA? They don't need to be part of the actual application, just part of the solution. It could potentially cause this kind of problem.

If it is indeed a bin/obj issue, then you'll be able to get to the good state by removing bin and obj, which is a pain, but will get you going until we can pin-point the issue.

[ghost]

Hi @333fred. We have added the "need-info" label to this issue, which indicates that we have an open question for you before we can take further action. This issue will be closed automatically in 7 days if we do not hear back from you by then - please feel free to re-open it if you come back to this issue after that time.

[333fred]

If it is indeed a bin/obj issue, then you'll be able to get to the good state by removing bin and obj, which is a pain, but will get you going until we can pin-point the issue.

I suspect this is correct, as I've noticed that doing complete rebuild seems to fix it. I'll grab the binlog from VS tonight.

[333fred]

Of course when I go to collect logs tonight what was crashing for me nearly every second build last night is doing nothing at all tonight... I'll keep trying to get a log.

[333fred]

Managed to get the logs from a build. It happened after a CTRL+F5 with minor changes (moved a comment around, essentially). As this is not an open source app I'm not going to attach the binlogs here, but will put them on a network share tomorrow for @jonathanpeppers and @dellis1972 to take a look at.

[333fred]

https://microsoft-my.sharepoint.com/:f:/p/frsilb/EuN4UGo4MLBGppt8K1Dn1HYB78DK7cSRA9OdtXMP9wS02A?e=R7d5TP should be accessible to MSFT folks. It has the binlogs from both build and deploy actions in VS, as well as the logcat output from adb shell setprop debug.mono.log default,assembly,mono_log_level=debug,mono_log_mask=all, the built apk, and the zipped bin directory from when it occured.

[Strypper]

I got this on .NET MAUI 7 when running release any suggestion ?

[333fred]

@Strypper in talking with @jonathanpeppers, a workaround should be putting <AndroidEnableMarshalMethods>false</AndroidEnableMarshalMethods> in your project file. However, if you're seeing this on .NET 7 and not 8, I suspect it may be something different, and the MAUI team might want to take a look at your logs 🙂.

[taublast]

If it is indeed a bin/obj issue, then you'll be able to get to the good state by removing bin and obj, which is a pain, but will get you going until we can pin-point the issue.

I suspect this is correct, as I've noticed that doing complete rebuild seems to fix it. I'll grab the binlog from VS tonight.

Just happened on Release for me, deleted bin/obj folders for a complete rebuild and the problem was gone. .Net 7.

[mgood7123]

cleaning does not fix it, as it will reappear sometimes when making seemingly valid changes

[jpobst]

Tracking this via #8253.