Maui Blazor template with Native AOT fails to display main page

[kotlarmilos]

Description

When attempting to use Native AOT with the Maui Blazor template targeting iOS with dotnet version 8.0.100-rtm.23479.1, the app fails to display the main page. No errors were retrieved from the app log. The app functions correctly with the Mono runtime.

Steps to Reproduce

1. Download the dotnet 10.0.100-rc.1.25451.107 version
2. Create a template app: dotnet new maui-blazor -n "MyMauiAppTemplate"
3. Publish the app using Native AOT: cd MyMauiAppTemplate && dotnet publish -f net10.0-ios /p:PublishAot=true /p:PublishAotUsingRuntimePack=true -r ios-arm64
4. Run the app using xharness: dotnet xharness apple run --app=bin/Release/net10.0-ios/ios-arm64/publish/Payload/MyMauiAppTemplate.app --targets=ios-device --output-directory=/tmp/out

Expected Behavior

The app should display the main page.

Actual Behavior

The app displays the error page.

Environment

Installed Workload Id	Manifest Version	Installation Source
maui	10.0.0-rc.1.25452.6/10.0.100-rc.1	SDK 10.0.100-rc.1

[kotlarmilos]

@dalexsoto Should we move this issue to the Maui repository?

[rolfbjarne]

@kotlarmilos my guess would be that this is because something was trimmed away, but do you know for sure?

[kotlarmilos]

Could be. Should we try to root some assemblies? Here is the compilation log:

/Users/miloskotlar/playground/MyMauiAppTemplate/obj/Release/net8.0-ios/ios-arm64/linked/Microsoft.iOS.dll : warning IL3053: Assembly 'Microsoft.iOS' produced AOT analysis warnings. [/Users/miloskotlar/playground/MyMauiAppTemplate/MyMauiAppTemplate.csproj::TargetFramework=net8.0-ios]
/Users/miloskotlar/playground/MyMauiAppTemplate/obj/Release/net8.0-ios/ios-arm64/linked/Microsoft.Maui.Controls.Xaml.dll : warning IL2104: Assembly 'Microsoft.Maui.Controls.Xaml' produced trim warnings. For more information see https://aka.ms/dotnet-illink/libraries [/Users/miloskotlar/playground/MyMauiAppTemplate/MyMauiAppTemplate.csproj::TargetFramework=net8.0-ios]
/Users/miloskotlar/playground/MyMauiAppTemplate/obj/Release/net8.0-ios/ios-arm64/linked/Microsoft.Maui.Controls.Xaml.dll : warning IL3053: Assembly 'Microsoft.Maui.Controls.Xaml' produced AOT analysis warnings. [/Users/miloskotlar/playground/MyMauiAppTemplate/MyMauiAppTemplate.csproj::TargetFramework=net8.0-ios]
/Users/miloskotlar/playground/MyMauiAppTemplate/obj/Release/net8.0-ios/ios-arm64/linked/Microsoft.Maui.Controls.dll : warning IL2104: Assembly 'Microsoft.Maui.Controls' produced trim warnings. For more information see https://aka.ms/dotnet-illink/libraries [/Users/miloskotlar/playground/MyMauiAppTemplate/MyMauiAppTemplate.csproj::TargetFramework=net8.0-ios]
/Users/miloskotlar/playground/MyMauiAppTemplate/obj/Release/net8.0-ios/ios-arm64/linked/Microsoft.Maui.dll : warning IL2104: Assembly 'Microsoft.Maui' produced trim warnings. For more information see https://aka.ms/dotnet-illink/libraries [/Users/miloskotlar/playground/MyMauiAppTemplate/MyMauiAppTemplate.csproj::TargetFramework=net8.0-ios]
/Users/miloskotlar/playground/MyMauiAppTemplate/obj/Release/net8.0-ios/ios-arm64/linked/Microsoft.Maui.dll : warning IL3053: Assembly 'Microsoft.Maui' produced AOT analysis warnings. [/Users/miloskotlar/playground/MyMauiAppTemplate/MyMauiAppTemplate.csproj::TargetFramework=net8.0-ios]
ILC : warning IL3000: Microsoft.AspNetCore.Components.WebView.WebViewManager.StaticWebAssetsLoader.ResolveRelativeToAssembly(): 'System.Reflection.Assembly.Location.get' always returns an empty string for assemblies embedded in a single-file app. If the path to the app directory is needed, consider calling 'System.AppContext.BaseDirectory'. [/Users/miloskotlar/playground/MyMauiAppTemplate/MyMauiAppTemplate.csproj::TargetFramework=net8.0-ios]
ILC : warning IL3000: Microsoft.AspNetCore.Components.WebView.WebViewManager.StaticWebAssetsLoader.ResolveRelativeToAssembly(): 'System.Reflection.Assembly.Location.get' always returns an empty string for assemblies embedded in a single-file app. If the path to the app directory is needed, consider calling 'System.AppContext.BaseDirectory'. [/Users/miloskotlar/playground/MyMauiAppTemplate/MyMauiAppTemplate.csproj::TargetFramework=net8.0-ios]
ILC : warning IL3000: Microsoft.AspNetCore.Components.WebView.WebViewManager.StaticWebAssetsLoader.ResolveRelativeToAssembly(): 'System.Reflection.Assembly.Location.get' always returns an empty string for assemblies embedded in a single-file app. If the path to the app directory is needed, consider calling 'System.AppContext.BaseDirectory'. [/Users/miloskotlar/playground/MyMauiAppTemplate/MyMauiAppTemplate.csproj::TargetFramework=net8.0-ios]
/Users/miloskotlar/playground/MyMauiAppTemplate/obj/Release/net8.0-ios/ios-arm64/linked/Microsoft.AspNetCore.Components.WebView.dll : warning IL2104: Assembly 'Microsoft.AspNetCore.Components.WebView' produced trim warnings. For more information see https://aka.ms/dotnet-illink/libraries [/Users/miloskotlar/playground/MyMauiAppTemplate/MyMauiAppTemplate.csproj::TargetFramework=net8.0-ios]
/Users/miloskotlar/playground/MyMauiAppTemplate/obj/Release/net8.0-ios/ios-arm64/linked/Microsoft.AspNetCore.Components.Web.dll : warning IL3053: Assembly 'Microsoft.AspNetCore.Components.Web' produced AOT analysis warnings. [/Users/miloskotlar/playground/MyMauiAppTemplate/MyMauiAppTemplate.csproj::TargetFramework=net8.0-ios]
/Users/miloskotlar/playground/MyMauiAppTemplate/obj/Release/net8.0-ios/ios-arm64/linked/Microsoft.AspNetCore.Components.dll : warning IL2104: Assembly 'Microsoft.AspNetCore.Components' produced trim warnings. For more information see https://aka.ms/dotnet-illink/libraries [/Users/miloskotlar/playground/MyMauiAppTemplate/MyMauiAppTemplate.csproj::TargetFramework=net8.0-ios]
/Users/miloskotlar/playground/MyMauiAppTemplate/obj/Release/net8.0-ios/ios-arm64/linked/Microsoft.AspNetCore.Components.WebView.dll : warning IL3053: Assembly 'Microsoft.AspNetCore.Components.WebView' produced AOT analysis warnings. [/Users/miloskotlar/playground/MyMauiAppTemplate/MyMauiAppTemplate.csproj::TargetFramework=net8.0-ios]
/Users/miloskotlar/playground/MyMauiAppTemplate/obj/Release/net8.0-ios/ios-arm64/linked/Microsoft.JSInterop.dll : warning IL3053: Assembly 'Microsoft.JSInterop' produced AOT analysis warnings. [/Users/miloskotlar/playground/MyMauiAppTemplate/MyMauiAppTemplate.csproj::TargetFramework=net8.0-ios]
/Users/miloskotlar/playground/MyMauiAppTemplate/obj/Release/net8.0-ios/ios-arm64/linked/Microsoft.JSInterop.dll : warning IL2104: Assembly 'Microsoft.JSInterop' produced trim warnings. For more information see https://aka.ms/dotnet-illink/libraries [/Users/miloskotlar/playground/MyMauiAppTemplate/MyMauiAppTemplate.csproj::TargetFramework=net8.0-ios]

[rolfbjarne]

@kotlarmilos do you know if this is still an issue in .NET 9/10?

[kotlarmilos]

I will try it again

[kotlarmilos]

This issue still persists. I tried to root trimming warnings, but it doesn’t seem to be related:

<?xml version="1.0" encoding="utf-8" ?>
<linker>
  <assembly fullname="Microsoft.AspNetCore.Components.WebView">
    <type fullname="Microsoft.AspNetCore.Components.WebView.WebViewManager" preserve="all" />
    <type fullname="Microsoft.AspNetCore.Components.WebView.WebViewManager.StaticWebAssetsLoader" preserve="all" />
    <type fullname="*" preserve="all" />
  </assembly>

  <assembly fullname="Microsoft.AspNetCore.Components.WebView.Maui">
    <type fullname="*" preserve="all" />
  </assembly>

  <assembly fullname="Microsoft.AspNetCore.Components">
    <type fullname="*" preserve="all" />
  </assembly>

  <assembly fullname="Microsoft.AspNetCore.Components.Web">
    <type fullname="*" preserve="all" />
  </assembly>

  <assembly fullname="Microsoft.JSInterop">
    <type fullname="*" preserve="all" />
  </assembly>

  <assembly fullname="MyMauiAppTemplateTest">
    <type fullname="*" preserve="all" />
  </assembly>

  <assembly fullname="System.Reflection">
    <type fullname="System.Reflection.Assembly" preserve="all" />
  </assembly>

  <assembly fullname="System.Runtime">
    <type fullname="System.AppContext" preserve="all" />
  </assembly>
</linker>