MSBuild support

[davidfowl]

Our msbuild project file support is shaky at best, This is an item to keep track of the pending work and challenges involved.

The problems:

• Differences between xbuild and msbuild (maybe we can get the oss msbuild building and running on mono to replace xbuild)
• Using the "right" version of msbuild
• Modifying the project file in a way that round trips with VS
  • Adding references

Hard/Impossible to fix:

• SDKs that aren't installed
• Customizations made to project files that require context (properties). Maybe we can solve this with configuration?

Brain dump from conversation with msbuild expert:

• VS 2012 and earlier (4.X): Uses the project ToolsVersion unless that ToolsVersion does not exist, in which case it falls back to 4.0
• VS 2013 and later (12.0+): Uses the "current" ToolsVersion (same as the engine, so 12.0 on msbuild 12, 14.0 on msbuild 14)
• The engine and tasks both have to run against the same version of the framework (*Microsoft.Build.Framework.dll, that is')
• The Tasks and Utilities assemblies are versioned in the file name, but that doesn't really matter as long as the version of M.B.Framework matches

[AndersNS]

Detecting the correct target platform needs to be done too. Omnisharp-roslyn seems to default to x86 for me. I worked around this by adding { "Platform", "AnyCPU"} the properties dictionary used by omnisharp-roslyn when creating a ProjectCollection.

Without this I got this error:

[ERROR:OmniSharp.MSBuild.MSBuildProjectSystem] The OutputPath property is not set for ? project 'NameSpace.CoolProject.csproj'. Please check to make sure that you have specified a valid combination of Configuration and Platform for this project. Configuration='Debug' Platform='x86'.

[nanoant]

I was today struggling with getting our MSBuild (VS 2015) projects to work with OmniSharp-roslyn, basically because it somehow defaults to $(Configuration)=Debug and $(Platform)=AnyCPU, but such platform does not exist neither in solution or project.

I have managed to get rid of the error simply settings the platform in ProjectFileInfo::Create to { "Platform", "x64" }, but this is really hackish way.

Is there any other, more elegant, probably via config.json way to set the platform?

[DustinCampbell]

Most MSBuild files default to $(Configuration)=Debug and $(Platform)=AnyCPU if they're not specified. I think we need a way for an OmniSharp host to change a project's Configuration and Platform dynamically (maybe some endpoint). This is also needed to set TargetFramework for multi-targeting projects.

[filipw]

I will close this issue as outdated. The msbuild support is much better since and many of the issues here have been addressed. There is a comprehensive look up process (bundled msbuild, mono msbuild, VS msbuild etc.). xbuild support has been dropped and there is a config setting to provide custom msbuild if needed. Nuget SDK resolver support has been added too giving support for Arcade, QDK and other custom SDK.

For the persisting problems, we have individual issues open.