F# core .NET framework on Linux build how-to

Question

I'm trying to build a F# project (console) on Ubuntu 17.10 (Mono 4.6.2) however I run into F# core .NET issues. For reference, I'm using Visual Studio Code 1.21.2 and ionide extensions (new project and FAKE build). Below is the output.

I've tried adding an explicit reference to different versions of Fsharp.core e.g. 4.2, 4.3.4 with no luck.

Where should I be looking at to sort this out?

Finished Target: InstallDotNetCLI
Starting Target: Restore (==> InstallDotNetCLI)
/home/lear/.local/share/dotnetcore/dotnet restore
  Restoring packages for /home/lear/src/fsTest/fsTest/fsTest.fsproj...
/home/lear/src/fsTest/fsTest/fsTest.fsproj : error NU1100: Unable to resolve 'FSharp.Core (>= 4.3.4)' for '.NETFramework,Version=v4.6.1'.
  Restore failed in 99.61 ms for /home/lear/src/fsTest/fsTest/fsTest.fsproj.
Running build failed.


 <ItemGroup>
    <PackageReference Update="FSharp.Core" Version="4.3.4" />
  </ItemGroup>

The project file looks like this:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net461</TargetFramework>
  </PropertyGroup>
  <ItemGroup>
    <ProjectReference Include="fsTest.fsproj">
      <Name>fsTest.fsproj</Name>
    </ProjectReference>
  </ItemGroup>
  <ItemGroup>
    <Compile Include="fsTest.fs" />
    <None Include="App.config" />
  </ItemGroup>
  <Import Project="..\.paket\Paket.Restore.targets" />
</Project>

I used this instructions as reference for my setup: Four easy steps for installing F# on Ubuntu Linux (2017-07-03)

Answer 1

The project file specifies the wrong TargetFramework. Changing that to e.g. netcoreapp2.0 Target Framework Moniker should fix the build.