MAUI app built in Debug configuration for CoreCLR fails to launch with `Didn't find class "mono.MonoRuntimeProvider"`

[vitek-karas]

Android framework version

net10.0-android (Preview)

Affected platform version

.NET 10 Preview 6 (daily build)

Description

java.lang.RuntimeException: Unable to get provider mono.MonoRuntimeProvider: java.lang.ClassNotFoundException: Didn't find class "mono.MonoRuntimeProvider" on path: DexPathList[[zip file "/data/app/~~CVaWjD2zE82iDvXUAslITQ==/com.companyname.t2clr-OQXNQlRgNBnjvFVvi3IQ6w==/base.apk"],nativeLibraryDirectories=[/data/app/~~CVaWjD2zE82iDvXUAslITQ==/com.companyname.t2clr-OQXNQlRgNBnjvFVvi3IQ6w==/lib/x86_64, /data/app/~~CVaWjD2zE82iDvXUAslITQ==/com.companyname.t2clr-OQXNQlRgNBnjvFVvi3IQ6w==/base.apk!/lib/x86_64, /system/lib64, /system_ext/lib64]]

Steps to Reproduce

(this was done on Windows, but it should probably work the same everywhere)
I installed the daily SDK from dotnet/dotnet - https://github.com/dotnet/dotnet/blob/main/docs/builds-table.md
Using this SDK (set via PATH and DOTNET_ROOT) I ran:

dotnet workload config --update-mode manifests
dotnet workload install maui
dotnet new maui
dotnet build -c Debug /p:UseMonoRuntime=false /t:Run -f net10.0-android

The app builds fine but crashes on launch - logcat shows:

FATAL EXCEPTION: main
Process: com.companyname.t2clr, PID: 10426
java.lang.RuntimeException: Unable to get provider mono.MonoRuntimeProvider: java.lang.ClassNotFoundException: Didn't find class "mono.MonoRuntimeProvider" on path: DexPathList[[zip file "/data/app/~~CVaWjD2zE82iDvXUAslITQ==/com.companyname.t2clr-OQXNQlRgNBnjvFVvi3IQ6w==/base.apk"],nativeLibraryDirectories=[/data/app/~~CVaWjD2zE82iDvXUAslITQ==/com.companyname.t2clr-OQXNQlRgNBnjvFVvi3IQ6w==/lib/x86_64, /data/app/~~CVaWjD2zE82iDvXUAslITQ==/com.companyname.t2clr-OQXNQlRgNBnjvFVvi3IQ6w==/base.apk!/lib/x86_64, /system/lib64, /system_ext/lib64]]
	at android.app.ActivityThread.installProvider(ActivityThread.java:7770)
	at android.app.ActivityThread.installContentProviders(ActivityThread.java:7276)
	at android.app.ActivityThread.handleBindApplication(ActivityThread.java:6983)
	at android.app.ActivityThread.-$$Nest$mhandleBindApplication(Unknown Source:0)
	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2236)
	at android.os.Handler.dispatchMessage(Handler.java:106)
	at android.os.Looper.loopOnce(Looper.java:205)
	at android.os.Looper.loop(Looper.java:294)
	at android.app.ActivityThread.main(ActivityThread.java:8177)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:552)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:971)
Caused by: java.lang.ClassNotFoundException: Didn't find class "mono.MonoRuntimeProvider" on path: DexPathList[[zip file "/data/app/~~CVaWjD2zE82iDvXUAslITQ==/com.companyname.t2clr-OQXNQlRgNBnjvFVvi3IQ6w==/base.apk"],nativeLibraryDirectories=[/data/app/~~CVaWjD2zE82iDvXUAslITQ==/com.companyname.t2clr-OQXNQlRgNBnjvFVvi3IQ6w==/lib/x86_64, /data/app/~~CVaWjD2zE82iDvXUAslITQ==/com.companyname.t2clr-OQXNQlRgNBnjvFVvi3IQ6w==/base.apk!/lib/x86_64, /system/lib64, /system_ext/lib64]]
	at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:259)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
	at android.app.AppComponentFactory.instantiateProvider(AppComponentFactory.java:147)
	at androidx.core.app.CoreComponentFactory.instantiateProvider(CoreComponentFactory.java:66)
	at android.app.ActivityThread.installProvider(ActivityThread.java:7754)
	at android.app.ActivityThread.installContentProviders(ActivityThread.java:7276) 
	at android.app.ActivityThread.handleBindApplication(ActivityThread.java:6983) 
	at android.app.ActivityThread.-$$Nest$mhandleBindApplication(Unknown Source:0) 
	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2236) 
	at android.os.Handler.dispatchMessage(Handler.java:106) 
	at android.os.Looper.loopOnce(Looper.java:205) 
	at android.os.Looper.loop(Looper.java:294) 
	at android.app.ActivityThread.main(ActivityThread.java:8177) 
	at java.lang.reflect.Method.invoke(Native Method) 
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:552) 
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:971) 

(the test app was called t2clr)

Did you find any workaround?

No response

Relevant log output

[jonathanpeppers]

@vitek-karas can you run dotnet workload list to see what version of the Android workload you had when this failed?

Last week, some of our builds were failing to push to the dotnet10 feed. Investigating here.

[jonathanpeppers]

@vitek-karas I think before you run:

dotnet workload install maui

You need dotnet new nugetconfig, and then also add:

<add key="dotnet10" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet10/nuget/v3/index.json" />

Then I could get it to find our build from main:

Installing workload manifest microsoft.net.sdk.android version 36.0.0-ci.main.140...

Where previously, it was installing a preview.3 build.

[vitek-karas]

I did that back then as well.
I tried again today - new daily build of SDK, install latest MAUI workloads... and it worked :-)
So I'll close this as it seems to be resolved in later builds.