Failed to build OmniSharp.Abstractions

[guardrex]

@troydai Following our comments at https://github.com/dotnet/cli/issues/1618#issuecomment-191970379

I don't have the DNX_UNSTABLE_FEED set on my Win10 laptop. It fully restores, but I ran into this (twice) attempting to build ...

[EDIT] Should I attempt to strip the dnx451 framework out of the project.json files and attempt a build on dnxcore50 or netstandardapp1.5?

[troydai]

Thanks for reporting this, @guardrex . You don't need to remove the framework. Everything is supposed to work right away.

I won't be able to repo this failure. But there are a few things you can begin with to solve this issue.

1. I suspect some cached old packages is misleading the restoring. Can you try clean the cached packages? Remove following folders: %userprofile%\.nuget\package and %localappdata%\NuGet\v3-cache.
2. If it still repos. Please enter the folder and OmniSharp.Abstractions and execute dotnet build the full build output should give us more clues.

[guardrex]

@troydai It was a fresh install of dotnet cli, VS Code, and DNVM/DNX on the laptop. Although, idk if the NuGet cache folder may have had packages prior to these installs.

I ran dotnet build from the folder, and it came out ...

[guardrex]

@troydai It seems to like dnxcore50 (and I forgot for a sec about the -f switch, but know now) ...

I'm going to proceed with an attempt to build the whole thing for dnxcore50 and report back.

[guardrex]

@troydai Doesn't look like it worked out. A few warnings thrown for dep conflicts. There is an error in the OmniSharp Log in VS Code ...

[EDIT] In spite of that error, it seems like OmniSharp is working. I get the flame and IntelliSense ...

[hal-ler]

For me the original error popped up from a lack of .NET 4.5.1 Reference Assemblies on my system. One recommended solution was to install VS. I found an alternate hack, by installing: https://www.microsoft.com/en-us/download/details.aspx?id=49978 and creating a copy for 4.5.1 of the folder "C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETFramework\v4.6.1".

[guardrex]

@hal-ler Excellent point. This laptop does not have those ref assemblies and that probably explains it.

Is the OmniSharp startup error "The project system 'DotNetProjectSystem' threw exception during initialization." of any concern?

When compiling for v4.5.1 without the ref assemblies, is the prior exception behavior "by-design" for a missing .NET 4.5.x framework?

[hal-ler]

I have only started playing around with the code recently, so take whatever I say with a grain of salt.

I was able to replicate your exception by convincing VS Code that a particular folder is a .NET Core project without a project.json residing within it. Omnisharp then tried to associate the folder with a workspace, but failed.

In my case the flame is on, but there is no IntelliSense, only editor suggestion for text (try to type "Console." and all the options should pop up). I suggest looking at your project.json file to see what is causing the issue.

[guardrex]

You are correct: The methods are not appearing with Intellisense. I thought it was working b/c when I opened a couple of code files, I wasn't getting bad ref indicators (squiggles) under method names. It's not performing look-ups, so it is not working.

[troydai]

@guardrex

I actually don't have a Windows environment without .NET installed. So I didn't test this Environment, my bad. In that case, yes the build failure is due to missing .NET 4.5.1 references. The solution @hal-ler gave will fix this.

On Mac and Linux this problem is solved by setting an environment variable: #412.

For the other issue, The project system 'DotNetProjectSystem' threw exception during initialization. means the project system can't be initialized correctly. Again this is due to the missing of .NET 4.5.1 reference assemblies on you machine. If your project target dnx451 or net451 framework, the DotNetProjectSystem will try to resolve the framework references.

On this note, I think a better error message as well as a choice to ignore entire target framework is a better user experience: dotnet/vscode-csharp#39

[guardrex]

@troydai

I see. I don't explicitly want to ref net451 (all of my apps are of the Core CLR variety), but I'm still having to use imports for unsupported packages ...

"netstandardapp1.5": {
    "imports": [ "dnxcore50", "portable-net45+win8" ]
}

Thanks @troydai and @hal-ler. I'm not sure I'll go to the trouble of installing .NET 4.5.1 or not. I might just rough it out for a few more weeks in hopes that VS Code gets baked-in goodness soon.

[guardrex]

@troydai @hal-ler ... yes ... @hal-ler ... thank you much ... your workaround worked for me. I installed the .NET Framework from https://www.microsoft.com/en-us/download/details.aspx?id=49978

I copied the folder ...

C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.6.1`

to a folder called ...

C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5.1`

The ./build.ps1 script ran to completion ...

My apps targeting netstandardapp1.5 (with the usual imports) are getting intellisence with the VS Code workspace setting ...

"csharp.omnisharp": "C:\\omnisharp-roslyn-dev\\artifacts\\publish\\OmniSharp\\dnxcore50\\
OmniSharp.exe"

I'm good. Thanks again to both of you for your help. I plan to stop pulling down DNX runtimes now, so let me know if that's going to be a problem.