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:

  <Choose>
    <When Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#')">
      <PropertyGroup>
        <FSharpSdkPathPrefix>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#</FSharpSdkPathPrefix>
      </PropertyGroup>
    </When>
    <Otherwise>
      <Choose>
        <When Condition="Exists('$(MSBuildExtensionsPath32)\..\..\..\..\Microsoft SDKs\F#')">
          <PropertyGroup>
            <FSharpSdkPathPrefix>$(MSBuildExtensionsPath32)\..\..\..\..\Microsoft SDKs\F#</FSharpSdkPathPrefix>
          </PropertyGroup>
        </When>
        <Otherwise>
          <PropertyGroup>
            <FSharpSdkPathPrefix></FSharpSdkPathPrefix>
          </PropertyGroup>
        </Otherwise>
      </Choose>
    </Otherwise>
  </Choose>
  <PropertyGroup>
    <FSharpSdkPathSuffix>Framework\v4.0\Microsoft.FSharp.Targets</FSharpSdkPathSuffix>
  </PropertyGroup>
  <Choose>
    <When Condition="'$(FSharpSdkPathPrefix)' == ''">
      <PropertyGroup>
        <FSharpTargetsPath></FSharpTargetsPath>
      </PropertyGroup>
    </When>
    <Otherwise>
      <Choose>
        <When Condition="Exists('$(FSharpSdkPathPrefix)\4.0\$(FSharpSdkPathSuffix)')">
          <PropertyGroup>
            <FSharpTargetsPath>$(FSharpSdkPathPrefix)\4.0\$(FSharpSdkPathSuffix)</FSharpTargetsPath>
          </PropertyGroup>
        </When>
        <Otherwise>
          <Choose>
            <When Condition="Exists('$(FSharpSdkPathPrefix)\3.1\$(FSharpSdkPathSuffix)')">
              <PropertyGroup>
                <FSharpTargetsPath>$(FSharpSdkPathPrefix)\3.1\$(FSharpSdkPathSuffix)</FSharpTargetsPath>
              </PropertyGroup>
            </When>
            <Otherwise>
              <Choose>
                <When Condition="Exists('$(FSharpSdkPathPrefix)\3.0\$(FSharpSdkPathSuffix)')">
                  <PropertyGroup>
                    <FSharpTargetsPath>$(FSharpSdkPathPrefix)\3.0\$(FSharpSdkPathSuffix)</FSharpTargetsPath>
                  </PropertyGroup>
                </When>
                <Otherwise>
                  <PropertyGroup>
                    <FSharpTargetsPath></FSharpTargetsPath>
                  </PropertyGroup>
                </Otherwise>
              </Choose>
            </Otherwise>
          </Choose>
        </Otherwise>
      </Choose>
    </Otherwise>
  </Choose>
  <Import Condition="'$(FSharpTargetsPath)' != ''" Project="$(FSharpTargetsPath)" />
  <Target Name="BeforeBuild">
    <Message Condition="'$(FSharpTargetsPath)' == ''" Importance="High" Text="F# SDK path was not found!" />
  </Target>

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.