.NET Core debugging with VS Code - "Only 64-bit processes can be debugged"

Question

I don't have VS 2017, and I'll be building a web front-end in VS Code anyway so I want to use VS Code.

Until .NET Standard 2.0 comes out, our libraries are also in 4.6.1, so I'm targetting net461 in my .NET Core csproj:

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>net461</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <Folder Include="wwwroot\" />
  </ItemGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore" Version="1.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="1.1.2" />
    <PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="1.1.1" />
  </ItemGroup>

</Project>

The project is the simplest dotnet new webapi starter app. I can build and run with dotnet build and dotnet run. I've also got the latest ms-vscode.csharp extension 1.8.1.

However, when I try attaching or debugging this application with VS Code I get the error

Failed to attach to process: Only 64-bit processes can be debugged

Even running from console, then attaching with the very simple configuration:

{
  "name": ".NET Core Attach",
  "type": "coreclr",
  "request": "attach",
  "processId": "${command:pickProcess}"
}

And selecting the process fails with this error. I've tried building the exe targeting x64 with:

<PropertyGroup>
  <TargetFramework>net461</TargetFramework>
  <Platform>x64</Platform>
</PropertyGroup>

But it produces the same error. Anyone know a fix? It seems to be because I'm targetting net461, does debugging .Net Core not support targeting other frameworks?

Answer 1

Version 1.9.0 of the ms-vscode.csharp extension added desktop CLR support.

Modify your launch.json file:

"type" : "clr",
"program" : "path to x64 version of the executable.exe"

To target x64, modify your .csproj file like so:

<PropertyGroup>
  <TargetFramework>net461</TargetFramework>
  <RuntimeIdentifier>win7-x64</RuntimeIdentifier>
</PropertyGroup>

An example program path after specifying the runtime id:

"program" : ${workspaceRoot}/src/bin/Debug/net461/win7-x64/example.exe