How to make F# projects which will work same on VS2010 / VS2013-preview?

Question

New F# projects comes with

  <Choose>
    <When Condition="'$(VisualStudioVersion)' == '11.0'">
      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
      </PropertyGroup>
    </When>
    <Otherwise>
      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
      </PropertyGroup>
    </Otherwise>
  </Choose>
  <Import Project="$(FSharpTargetsPath)" />

msbuild just fails with it so I even can't write an build script based on this project file.

My solution:

<Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v12.0\FSharp\Microsoft.FSharp.Targets" />

I set v12.0 instead of $(VisualStudioVersion) because VisualStudioVersion is 11 for my msbuild. So but this breaks compatibility with other Visual Studio versions.

I guess I need to make something alike

<FSharpTargetsPath Condition="'$(VisualStudioVersion)' == '11.0'">$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>

and

<FSharpTargetsPath Condition="'$(VisualStudioVersion)' == '12.0'">$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v12.0\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>

But that even doesn't look alike good solution. Is there proper way?

Also I have problems with running 3.0 F# compiler fsc.exe and software alike FAKE :

Could not load file or assembly FSharp.Core, Version=4.3.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies

So how to not break compatibility between 3.0 / msbuild and 3.1 and newer VS2013-preview stuff ?

Answer 1

The more specific answer that I guess Danny should have given is:

<PropertyGroup Condition="'$(FSharpTargetsPath)' == '' OR (!(Exists('$(FSharpTargetsPath)')))">
  <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Common7\IDE\CommonExtensions\Microsoft\FSharp\Tools\Microsoft.FSharp.Targets</FSharpTargetsPath>
</PropertyGroup>
<PropertyGroup Condition="'$(FSharpTargetsPath)' == '' OR (!(Exists('$(FSharpTargetsPath)')))">
  <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
</PropertyGroup>
<PropertyGroup Condition="'$(FSharpTargetsPath)' == '' OR (!(Exists('$(FSharpTargetsPath)')))">
  <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\4.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
</PropertyGroup>
<PropertyGroup Condition="'$(FSharpTargetsPath)' == '' OR (!(Exists('$(FSharpTargetsPath)')))">
  <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.1\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
</PropertyGroup>
<PropertyGroup Condition="'$(FSharpTargetsPath)' == '' OR (!(Exists('$(FSharpTargetsPath)')))">
  <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
</PropertyGroup>
<Import Project="$(FSharpTargetsPath)" />

This should work with all versions.

Answer 2

I would start by creating projects in both versions and diffing the project files. If you build a project file that contains the superset of both files, with appropriate Condition attributes so that each version of VS reads the correct parts, in theory it should work.