Hey there! I’ve hit this exact IL2CPU error a handful of times while building Cosmos-based OS projects, so let me walk you through the most common fixes and troubleshooting steps that usually get things back on track:

• Audit your code for unsupported .NET features
  IL2CPU doesn’t play nice with all standard .NET APIs. Things like System.Collections.Generic.List<T> (swap it out for Cosmos’s own Cosmos.Core.Collections.List<int>), reflection, async/await, or LINQ will almost certainly trigger this error. Go through your 350 lines and flag any code using non-Cosmos-compatible libraries or syntax.

• Confirm Cosmos and .NET version compatibility
  Stable versions of Cosmos are way more reliable than nightly builds—stick to a release tag if you’re still iterating. Also, double-check that your project’s .csproj TargetFramework matches the version your Cosmos NuGet packages expect. Mismatched SDK and library versions are a super common cause of IL2CPU failures.

• Clean and rebuild from scratch
  Cached build artifacts in bin/obj folders often cause weird, unexplainable IL2CPU glitches. Right-click your project → Clean, then delete those folders manually before doing a fresh rebuild. This wipes out any corrupted intermediate files that might be breaking the process.

• Check for invalid IL in low-level code
  If you’re using unsafe code, custom struct layouts, or direct memory operations, even a tiny mistake (like an uninitialized pointer or misaligned struct) can crash IL2CPU. Try commenting out sections of your code incrementally to isolate which part is triggering the error. Adding simple debug prints (using Cosmos’s Console.WriteLine equivalent) can also help pinpoint the issue.

• Enable verbose IL2CPU logging
  To get a detailed breakdown of what’s failing, add this to your project’s .csproj file:

  <PropertyGroup>
    <CosmosIL2CPULogLevel>Verbose</CosmosIL2CPULogLevel>
  </PropertyGroup>
  

  The build log will now show exactly which method, assembly, or IL instruction is causing the invocation to fail—this is usually the fastest way to zero in on the problem.

• Verify all required Cosmos dependencies are installed
  Make sure you have Cosmos.Core, Cosmos.Kernel, and Cosmos.Build.Tasks in your NuGet packages. Missing even one core dependency can lead to incomplete IL processing that triggers this error.

If none of these steps resolve the issue, sharing a minimal snippet of the code you suspect is problematic would help narrow things down further!

内容的提问来源于stack exchange，提问作者Dragon Softwares