Roslyn: MSBuildWorkspace can't open a VS2017 project (.Net Framework or .NetStandard)

[philippe-lavoie]

Version Used:
VS2017 15.3.4 and 15.4 preview
Steps to Reproduce:

1. Compile the following code inside a new project "TestWorkspace.csproj" targeting .net 47
2. add reference to Microsoft.Build.Tasks and Microsoft.CodeAnalysis.CSharp.Workspaces

You can target a command line project or a unit test one. Can't get this to work in either cases.

Expected Behavior:
The number of documents should be greater than 0 since program.cs exists in the project you created. (return true)

Actual Behavior:
Everything is empty. (return false)

Code to use

    public bool TestLoadingProject()
    {
        var assemblyLocation = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
        var fileInfo = new FileInfo(assemblyLocation);
        var folder = fileInfo.Directory;
        var parent = folder.Parent;

        var projectPath = Path.Combine(parent.FullName, "TestWorkspace.csproj");

        var msWorkspace = MSBuildWorkspace.Create();
        var project = msWorkspace.OpenProjectAsync(projectPath).Result;
        var compilation = project.GetCompilationAsync().Result;
        return project.DocumentIds.Count > 0;
    }

I've been using Roslyn for a while and with latest VS2017 and netstadnard 2, reading MSBuildWorkspace is not working from a command line or unit test. I think it still works inside a VSIX. This is beyound annoying, I don't want to ship a VSIX without doing unit tests... My real test case is to analyse standard2 library, not even sure that will work. It seems such a basic usage of MSBuildWorkspace...

[Pilchie]

Tagging @DustinCampbell.

[philippe-lavoie]

I've hooked up the WorkspaceEvent and when trying to load a .net 4.7 csproj file, it returns

Msbuild failed when processing the file '...' with message: The tools version "15.0" is unrecognized. Available tools versions are "12.0", "2.0", "3.5", "4.0"

When trying to load a .net standard 2 project, I get the following:

Msbuild failed when processing the file '...' with message: The SDK 'Microsoft.NET.Sdk' specified could not be found.

So... it looks like version 15 is not supported. I seriously doubt that I'm the first in the world that tries to load a .net framework project from VS2017. I'm also concerned about the error for loading a .net standard project.

For our project, we are using .net standard everywhere and we want to provide VSIX extensions to help the development effort. By definition, it means a .net framework process needs to be able to read a .net standard project. My original thinking was that since .netstandard is supported by .net framework, it shouldn't be a problem.... is that assumption wrong ?

[DustinCampbell]

@phillippe-lavoie: There are couple of reasons why this might happen. My guess is that you're running into a bug where MSBuild cannot locate VS 2017 on your machine. Thus, it doesn't find the "15.0" toolset, which is located beneath the Visual Studio 2017 directory. There are a few issues that this might happen:

1. You need to pull newer Microsoft.Build and Microsoft.Build.Framework packages into your project. Note that this might also require adding binding redirects. See https://github.com/dotnet/roslyn/issues/21644 for the necessary binding redirects.
2. The name of your application includes "MSBuild" in its exe name. I've run into this one a couple of times. (https://github.com/Microsoft/msbuild/issues/2194)

[philippe-lavoie]

I might have made progress, but it's still not working. In the case of a unit test, I'm still getting the above behavior. In the case of a command line tool, I get a different output. The code is at TestingWorkspaceLoading and it isolates the issue for both command line and unit tests import of a VS2017 project (both .net framework and .net standard)

Tests are starting
TestLoadingFrameworkProject fail 3036
System.AggregateException: One or more errors occurred. ---> System.Exception: Msbuild failed when processing the file 'C:\Projects\T\TestingWorkspaceLoading\TestingWorkspaceLoading\ADotNetFrameworkLibrary\ADotNetFrameworkLibrary.csproj' with message: The imported project "C:\Projects\T\TestingWorkspaceLoading\TestingWorkspaceLoading\FromCommandLine\bin\Debug\Roslyn\Microsoft.CSharp.Core.targets"
TestLoadingStandardProject fail 440
System.AggregateException: One or more errors occurred. ---> System.Exception: Msbuild failed when processing the file 'C:\Projects\T\TestingWorkspaceLoading\TestingWorkspaceLoading\ADotNetStandardLibrary\ADotNetStandardLibrary.csproj' with message: The SDK 'Microsoft.NET.Sdk' specified could not be found. C:\Projects\T\TestingWorkspaceLoading\TestingWorkspaceLoading\ADotNetStandardLibrary\ADotNe

The error was a bit long and the output of the command line truncates it, but it's actually the following

Msbuild failed when processing the file 'C:\Projects\T\TestingWorkspaceLoading\TestingWorkspaceLoading\ADotNetFrameworkLibrary\ADotNetFrameworkLibrary.csproj' with message: The imported project "C:\Projects\T\TestingWorkspaceLoading\TestingWorkspaceLoading\FromCommandLine\bin\Debug\Roslyn\Microsoft.CSharp.Core.targets" was not found. Confirm that the path in the declaration is correct, and that the file exists on disk. C:\Projects\T\TestingWorkspaceLoading\TestingWorkspaceLoading\FromCommandLine\bin\Debug\Microsoft.CSharp.CurrentVersion.targets

[philippe-lavoie]

As seen on my test project, I added all binding redirects and every latest version of Microsoft.Build.* needed.

[philippe-lavoie]

Sorry to bother you with this again, but I'd really (and do mean REALLY) like the ability to unit tests my visual studio extensions. For this, I need the ability to load a workspace inside a unit test. Any traction on this ?