tmijieux
commented
2 years ago I think i found a workaround for the place i was stuck for using xabuild, for a reason that i did not understand yet, NuGetTargets has its value set, as if VisualStudioVersion was 15.0 and the import is skipped, although VisualStudioVersion seems to be 17.0 in everywhere i look at it in my binlog.
(this is file from visual studio, imported through the Current symlink)
<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<PropertyGroup>
<NuGetTargets Condition="'$(NuGetTargets)'==''">$(MSBuildExtensionsPath)\Microsoft\NuGet\$(VisualStudioVersion)\Microsoft.NuGet.targets</NuGetTargets>
</PropertyGroup>
<Import Condition="Exists('$(NuGetTargets)') and '$(SkipImportNuGetBuildTargets)' != 'true'" Project="$(NuGetTargets)" />
</Project>if i set NuGetTargets to the right value before any import , the packagereference now works correctly
ghost
grendello
lambdageek
FelixZY
gsgou
Android application type
Classic Xamarin.Android (MonoAndroid11.0, MonoAndroid12.0, etc.)
Affected platform version
VS2022 17.0.1, 17.0.2 VS2019(latest, probably https://docs.microsoft.com/fr-fr/visualstudio/releases/2019/release-notes#16.11.5 but i uninstalled it since)
Description
I am currently under investigation of a native crash very similar to https://github.com/xamarin/xamarin-android/issues/3892
the relevant part of the log seems to be this message
Assertion: should not be reached at /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/mono/sgen/sgen-scan-object.h:91(see here this is actually a header file that contains preprocessor templated code and is included in multiple position in the code) that seems to indicate some portion of theorically unreachable code was reached in the code that is scanning for references in the sgen garbage collector, specifically it looked for an field in a native struct to determine what type of object it is currently looking at, but the switch did not match any case which seems to indicate what it is looking at is not what it expected to be (this could be maybe memory corruption?)My intuition for now is that is has something to do with some c# code we introduced (tough i am not 100% sure about that and my rational self rather believe that it is unlikely since it looks like a native crash). It started crashing in a production release (we never reproduced during development until it happened in production). In the new release, we did update some nugets but even after reverting the nuget versions, the crash was still there. But when we rebuilt (with the same visual-studio/xamarin-android version that was producing the crashing builds) an old version that we knew was not triggering this crash initially, then the new build of that old version was still not crashing.
At first we did thought the crash was more likely to happen under low memory condition (and it is likely because it happens when gc is running) and we looked for memory leaks. We found some but even after fixing most of them the crashes are still there.
At the times when we were looking for leaks, we tried to do a "git bisect" to find where the problem was coming from but we were more focused on the leaks when we did this, so I think I should probably retry to do a "git bisect" focusing on trying to trigger the crash (but this is a little problematic because we did not found a way yet to reproduce this issue systematically on any of our test devices)
Things i've looked at that I thought could have been related but does not really look similar: https://docs.microsoft.com/en-us/xamarin/android/release-notes/11/11.1#corrected-garbage-collection-behavior-for-android-bindings-and-bindings-projects
Our app is a xamarin.forms app there is the list of nugets we use
xml package references
```xml
all
runtime; build; native; contentfiles; analyzers; buildtransitive
./OpenId.AppAuth.Android.dll
So we have a few bindings libraries (com.onesignal, openid.appauth,...) and the main native library here is SkiaSharp.
What i am currently stuck at: I succeed at binding gdb on my app like describe here (https://github.com/xamarin/xamarin-android/blob/main/Documentation/workflow/DevelopmentTips.md#attaching-gdb-using-visual-studio-on-windows) and i think i also got my app to trigger my crash once, but there was virtually no information when printing the backtrace (just interrogation mark)
My current goal is to build xamarin-android to get to natively debug my app and try to get more information out of it (with debug symbols in mono sgen and stuff, i would like to have Address and undefined behavior sanitizer on mono and skiasharp if possible )
I successfully built xamarin-android and xabuild (I checkout the d17-0 branch because i wanted to get the same version i have in my current visual studio 2022, is that a good idea or not?) I had to change to platformtarget of xabuild.csproj to x64 because the msbuild in vs2022 seems to be 64bits. if i run xabuild on the samples/HelloWorld project i can build and deploy an app but if I add a packagereference to xamarin.forms
diff
```diff diff --git a/samples/HelloWorld/HelloWorld.csproj b/samples/HelloWorld/HelloWorld.csproj index 2b5391ee..092a8090 100644 --- a/samples/HelloWorld/HelloWorld.csproj +++ b/samples/HelloWorld/HelloWorld.csproj @@ -52,6 +52,7 @@{6BE66B30-9346-4DA6-B09A-0CDC1DFE33C2}
HelloLibrary
+
Somehow the referenced assemblies from the nuget does not get added to the csc command line and the project fails to build (
C:\src\xamarin-android\samples\HelloWorld\MainActivity.cs(4,15): error CS0234: The type or namespace name 'Forms' does not exist in the namespace 'Xamari n' (are you missing an assembly reference?) [C:\src\xamarin-android\samples\HelloWorld\HelloWorld.csproj]) just like what would happen if the packagereference was not there, The same issue happens with my own project so i am currently unable to build my project with xabuild. (maybe I have something in my env that is hindering correct behavior or there is an issue with xabuild itself? if someone have an idea about this issue that would be helpful, i attached a binlog for the modified HelloWorld) msbuild.binlog.zipfor items mentionned in the referenced issue: I tried disabling the concurrent garbage collector, but the app suffered a slowdown, and it did not seems to fix the crashes. The crash seems to happens even on debug builds, not only on appstore releases, but maybe less often... What I did not try yet:
Steps to Reproduce
It is still very hard even for our team to reproduce (especially on emulator where it seems to happens very rarely)
Did you find any workaround?
Not yet, reverting my app to an old version did the trick for now but we cannot go forward until we find what is causing this.
Relevant log output
development environment information
``` Microsoft Visual Studio Community 2022 Version 17.0.2 VisualStudio.17.Release/17.0.2+31919.166 Microsoft .NET Framework Version 4.8.04161 Installed Version: Community Visual C++ 2022 00482-90000-00000-AA768 Microsoft Visual C++ 2022 ASP.NET and Web Tools 2019 17.0.793.11735 ASP.NET and Web Tools 2019 Azure App Service Tools v3.0.0 17.0.793.11735 Azure App Service Tools v3.0.0 C# Tools 4.0.1-1.21568.1+6ab6601178d9fba8c680b56934cd1742e0816bff C# components used in the IDE. Depending on your project type and settings, a different version of the compiler may be used. Common Azure Tools 1.10 Provides common services for use by Azure Mobile Services and Microsoft Azure Tools. Extensibility Message Bus 1.2.6 (master@34d6af2) Provides common messaging-based MEF services for loosely coupled Visual Studio extension components communication and integration. Microsoft JVM Debugger 1.0 Provides support for connecting the Visual Studio debugger to JDWP compatible Java Virtual Machines Microsoft MI-Based Debugger 1.0 Provides support for connecting Visual Studio to MI compatible debuggers Microsoft Visual C++ Wizards 1.0 Microsoft Visual C++ Wizards Microsoft Visual Studio VC Package 1.0 Microsoft Visual Studio VC Package Mono Debugging for Visual Studio 17.0.11 (54f19d2) Support for debugging Mono processes with Visual Studio. NuGet Package Manager 6.0.1 NuGet Package Manager in Visual Studio. For more information about NuGet, visit https://docs.nuget.org/ ProjectServicesPackage Extension 1.0 ProjectServicesPackage Visual Studio Extension Detailed Info Test Adapter for Boost.Test 1.0 Enables Visual Studio's testing tools with unit tests written for Boost.Test. The use terms and Third Party Notices are available in the extension installation directory. Test Adapter for Google Test 1.0 Enables Visual Studio's testing tools with unit tests written for Google Test. The use terms and Third Party Notices are available in the extension installation directory. TypeScript Tools 17.0.1001.2002 TypeScript Tools for Microsoft Visual Studio Visual Basic Tools 4.0.1-1.21568.1+6ab6601178d9fba8c680b56934cd1742e0816bff Visual Basic components used in the IDE. Depending on your project type and settings, a different version of the compiler may be used. Visual C++ for Cross Platform Mobile Development (Android) 17.0.31822.380 Visual C++ for Cross Platform Mobile Development (Android) Visual F# Tools 17.0.0-beta.21522.2+6d626ff0752a77d339f609b4d361787dc9ca93a5 Microsoft Visual F# Tools Visual Studio Code Debug Adapter Host Package 1.0 Interop layer for hosting Visual Studio Code debug adapters in Visual Studio Visual Studio IntelliCode 2.2 AI-assisted development for Visual Studio. Visual Studio Tools for CMake 1.0 Visual Studio Tools for CMake VisualStudio.DeviceLog 1.0 Information about my package VisualStudio.Foo 1.0 Information about my package VisualStudio.Mac 1.0 Mac Extension for Visual Studio Xamarin 17.0.0.341 (d17-0@ac52790) Visual Studio extension to enable development for Xamarin.iOS and Xamarin.Android. Xamarin Designer 17.0.0.182 (remotes/origin/d17-0@ea204898d) Visual Studio extension to enable Xamarin Designer tools in Visual Studio. Xamarin Templates 17.0.17 (9e779b0) Templates for building iOS, Android, and Windows apps with Xamarin and Xamarin.Forms. Xamarin.Android SDK 12.1.0.5 (d17-0/6b0e6b2) Xamarin.Android Reference Assemblies and MSBuild support. Mono: c633fe9 Java.Interop: xamarin/java.interop/d17-0@febb1367 ProGuard: Guardsquare/proguard/v7.0.1@912d149 SQLite: xamarin/sqlite/3.36.0@a575761 Xamarin.Android Tools: xamarin/xamarin-android-tools/d17-0@a5194e9 Xamarin.iOS and Xamarin.Mac SDK 15.2.0.17 (738fde344) Xamarin.iOS and Xamarin.Mac Reference Assemblies and MSBuild support. ```