FileNotFoundException on trying to Instrument AspNetCore application

[Varkeychan Jacob]

Bug Report

Symptom

Getting this error on trying to instrument AspNetCore application

PS C:\Users\varkeychan_jacob\dotnetserver\HttpServer\bin\Debug\net8.0> .\HttpServer.exe
info: Microsoft.Hosting.Lifetime[14]
      Now listening on: http://localhost:5000
crit: Microsoft.AspNetCore.Hosting.Diagnostics[11]
      Hosting startup assembly exception
      System.InvalidOperationException: Startup assembly OpenTelemetry.AutoInstrumentation.AspNetCoreBootstrapper failed to execute. See the inner exception for more details.
       ---> System.IO.FileNotFoundException: Could not load file or assembly 'OpenTelemetry.AutoInstrumentation.AspNetCoreBootstrapper, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified.
      File name: 'OpenTelemetry.AutoInstrumentation.AspNetCoreBootstrapper, Culture=neutral, PublicKeyToken=null'
         at System.Reflection.RuntimeAssembly.<InternalLoad>g____PInvoke|49_0(NativeAssemblyNameParts* __pAssemblyNameParts_native, ObjectHandleOnStack __requestingAssembly_native, StackCrawlMarkHandle __stackMark_native, Int32 __throwOnFileNotFound_native, ObjectHandleOnStack __assemblyLoadContext_native, ObjectHandleOnStack __retAssembly_native)
         at System.Reflection.RuntimeAssembly.InternalLoad(NativeAssemblyNameParts* pAssemblyNameParts, ObjectHandleOnStack requestingAssembly, StackCrawlMarkHandle stackMark, Boolean throwOnFileNotFound, ObjectHandleOnStack assemblyLoadContext, ObjectHandleOnStack retAssembly)
         at System.Reflection.RuntimeAssembly.InternalLoad(AssemblyName assemblyName, StackCrawlMark& stackMark, AssemblyLoadContext assemblyLoadContext, RuntimeAssembly requestingAssembly, Boolean throwOnFileNotFound)
         at System.Reflection.Assembly.Load(AssemblyName assemblyRef)
         at Microsoft.AspNetCore.Hosting.GenericWebHostBuilder.ExecuteHostingStartups()
         --- End of inner exception stack trace ---

Expected behavior
App gets instrumented

Runtime environment (please complete the following information):

• OpenTelemetry Automatic Instrumentation version: v1.2.0
• OS: Windows Server 2022 Datacenter 21H2
• .NET version: NET Framework 4.8.1, .NET Core 8.0.100

Additional context
Add any other context about the problem here.

Reproduce

Steps to reproduce the behavior:

1. Proceed as per steps mentioned here: https://opentelemetry.io/docs/instrumentation/net/automatic/#windows-powershell
2. On running .\MyApp.exe, it'll throw the above error

[Piotr Kiełkowicz]

@varkey98, could you please create Minimal, Reproducible Example? It should include all steps used to build, copy files. Without this, it will be hard to reproduce.

[Varkeychan Jacob]

Sure, please give me some time

[Varkeychan Jacob]

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

app.MapPost("/hello", async delegate(HttpContext context)
{
    HttpRequest request = context.Request;
    
    StreamReader reader = new StreamReader(context.Request.Body, Encoding.UTF8);
    string body = getRequestBody(context.Request.Body);
   
    if (string.IsNullOrWhiteSpace(body))
    {
        await context.Response.Body.WriteAsync(Encoding.ASCII.GetBytes("Hello World!"));
    }
    else
    {
        await context.Response.Body.WriteAsync(Encoding.ASCII.GetBytes(body));

    }
});

app.Run();

Please find my application code

[Piotr Kiełkowicz]

It does not looks like steps to reproduce. It is just a code. Pleas provide exact steps similar to:

1..Execute dotnet build xxxx in forlder.
2. Execute yyyyy
3. Execute zzzz to instrument application.
Etc.

[Paulo Janotti]

SIG: no repro at this moment, can re-open if needed.