[WebToolsE2E] Fail to debug the 11.0 Blazor WASM project using VS Code with error "System.IO.FileNotFoundException: Cannot start debug proxy because it cannot be found"

[EmilyFeng97]

REGRESSION INFO: .Not repro on 10.0 project

INSTALL STEPS:

1. Clean Win11 x64 25h2 ENU
2. Install the .NET 11.0 alpha 1 SDK: https://aka.ms/dotnet/11.0.1xx/daily/dotnet-sdk-win-x64.exe
3. Add feed: https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet11/nuget/v3/index.json
4. Install VS Code stable - 1.108.0
5. Install release C# DK1.90.2(include C#2.110.4)

Platform

• Windows
• macOS
• Linux

Repro Steps

1. Open a normal Command Prompt
2. Create a Blazor Web App for WebAssembly, open it in VS Code

dotnet new blazor -int WebAssembly -o blazorwasmhosted
cd blazorwasmhosted
code .

3. Right click the project > Debug > Start New Instance

Note:

1. This issue does not repro on Blazor Web App for Server/None project.
2. This issue also repro on Blazor Web App for Auto and Blazor WebAssembly Standalone App.
3. This issue does not repro when debugging with VS 18.4 or run using dotnet watch.

Actual Result
Fail to debug 11.0 Blazor Web App for wasm/auto project.

Error Log

------------------------------------------------------------------------------
You may only use the Microsoft Visual Studio .NET/C/C++ Debugger (vsdbg) with
Visual Studio Code, Visual Studio or Visual Studio for Mac software to help you
develop and test your applications.
------------------------------------------------------------------------------
dbug: Microsoft.AspNetCore.Watch.BrowserRefresh.BlazorWasmHotReloadMiddleware[0]
      Middleware loaded
Microsoft.AspNetCore.Watch.BrowserRefresh.BlazorWasmHotReloadMiddleware: Debug: Middleware loaded
Microsoft.AspNetCore.Watch.BrowserRefresh.BrowserScriptMiddleware: Debug: Middleware loaded. Script /_framework/aspnetcore-browser-refresh.js (16459 B).
dbug: Microsoft.AspNetCore.Watch.BrowserRefresh.BrowserScriptMiddleware[0]
      Middleware loaded. Script /_framework/aspnetcore-browser-refresh.js (16459 B).
dbug: Microsoft.AspNetCore.Watch.BrowserRefresh.BrowserScriptMiddleware[0]
      Middleware loaded. Script /_framework/blazor-hotreload.js (799 B).
Microsoft.AspNetCore.Watch.BrowserRefresh.BrowserScriptMiddleware: Debug: Middleware loaded. Script /_framework/blazor-hotreload.js (799 B).
dbug: Microsoft.AspNetCore.Watch.BrowserRefresh.BrowserRefreshMiddleware[0]
      Middleware loaded: DOTNET_MODIFIABLE_ASSEMBLIES=debug, __ASPNETCORE_BROWSER_TOOLS=true
Microsoft.AspNetCore.Watch.BrowserRefresh.BrowserRefreshMiddleware: Debug: Middleware loaded: DOTNET_MODIFIABLE_ASSEMBLIES=debug, __ASPNETCORE_BROWSER_TOOLS=true
info: Microsoft.Hosting.Lifetime[14]
      Now listening on: http://localhost:5063
Microsoft.Hosting.Lifetime: Information: Now listening on: http://localhost:5063
info: Microsoft.Hosting.Lifetime[0]
      Application started. Press Ctrl+C to shut down.
Microsoft.Hosting.Lifetime: Information: Application started. Press Ctrl+C to shut down.
info: Microsoft.Hosting.Lifetime[0]
      Hosting environment: Development
Microsoft.Hosting.Lifetime: Information: Hosting environment: Development
info: Microsoft.Hosting.Lifetime[0]
      Content root path: C:\Users\v-xinyfe\blazorwasmhosted\blazorwasmhosted
Microsoft.Hosting.Lifetime: Information: Content root path: C:\Users\v-xinyfe\blazorwasmhosted\blazorwasmhosted
fail: Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware[1]
      An unhandled exception has occurred while executing the request.
      System.IO.FileNotFoundException: Cannot start debug proxy because it cannot be found at 'C:\Users\v-xinyfe\blazorwasmhosted\blazorwasmhosted\bin\Debug\net11.0\BlazorDebugProxy\BrowserDebugHost.dll'
         at Microsoft.AspNetCore.Builder.DebugProxyLauncher.LocateDebugProxyExecutable(IWebHostEnvironment environment)
         at Microsoft.AspNetCore.Builder.DebugProxyLauncher.LaunchAndGetUrl(IServiceProvider serviceProvider, String devToolsHost, Boolean isFirefox)
         at Microsoft.AspNetCore.Builder.WebAssemblyNetDebugProxyAppBuilderExtensions.<>c.<<UseWebAssemblyDebugging>b__0_1>d.MoveNext()
      --- End of stack trace from previous location ---
         at Microsoft.AspNetCore.Builder.Extensions.MapMiddleware.InvokeCore(HttpContext context, PathString matchedPath, PathString remainingPath)
         at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddlewareImpl.Invoke(HttpContext context)
Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware: Error: An unhandled exception has occurred while executing the request.

System.IO.FileNotFoundException: Cannot start debug proxy because it cannot be found at 'C:\Users\v-xinyfe\blazorwasmhosted\blazorwasmhosted\bin\Debug\net11.0\BlazorDebugProxy\BrowserDebugHost.dll'
   at Microsoft.AspNetCore.Builder.DebugProxyLauncher.LocateDebugProxyExecutable(IWebHostEnvironment environment)
   at Microsoft.AspNetCore.Builder.DebugProxyLauncher.LaunchAndGetUrl(IServiceProvider serviceProvider, String devToolsHost, Boolean isFirefox)
   at Microsoft.AspNetCore.Builder.WebAssemblyNetDebugProxyAppBuilderExtensions.<>c.<<UseWebAssemblyDebugging>b__0_1>d.MoveNext()
--- End of stack trace from previous location ---
   at Microsoft.AspNetCore.Builder.Extensions.MapMiddleware.InvokeCore(HttpContext context, PathString matchedPath, PathString remainingPath)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddlewareImpl.Invoke(HttpContext context)

[claudiaregio]

@LittleLittleCloud could you investigate this one?

[LittleLittleCloud]

Tracking by https://devdiv.visualstudio.com/DevDiv/_workitems/edit/2680189

[EmilyFeng97]

Verify this issue on the latest build of .NET 11.0-preview SDK, it work well. Close it as Fix.