Omnisharp-vscode: The SDK 'Microsoft.NET.Sdk.Web' specified could not be found.

[tonyranieri]

Was asked to create new issue on https://github.com/OmniSharp/omnisharp-vscode/issues/2876

Environment data

dotnet --info output:

PS C:sourcepocomnisharp-issue> dotnet --info
.NET Core SDK (reflecting any global.json):
Version: 2.2.203
Commit: e5bab63eca

Runtime Environment:
OS Name: Windows
OS Version: 10.0.14393
OS Platform: Windows
RID: win10-x64
Base Path: C:Program Filesdotnetsdk2.2.203

Host (useful for support):
Version: 2.2.4
Commit: f95848e524

.NET Core SDKs installed:
1.0.0 [C:Program Filesdotnetsdk]
1.0.1 [C:Program Filesdotnetsdk]
1.0.4 [C:Program Filesdotnetsdk]
2.0.0 [C:Program Filesdotnetsdk]
2.0.2 [C:Program Filesdotnetsdk]
2.1.4 [C:Program Filesdotnetsdk]
2.1.300 [C:Program Filesdotnetsdk]
2.1.302 [C:Program Filesdotnetsdk]
2.2.104 [C:Program Filesdotnetsdk]
2.2.203 [C:Program Filesdotnetsdk]

.NET Core runtimes installed:
Microsoft.AspNetCore.All 2.1.0 [C:Program FilesdotnetsharedMicrosoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.1.2 [C:Program FilesdotnetsharedMicrosoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.2.2 [C:Program FilesdotnetsharedMicrosoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.2.4 [C:Program FilesdotnetsharedMicrosoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.1.0 [C:Program FilesdotnetsharedMicrosoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.1.2 [C:Program FilesdotnetsharedMicrosoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.2.2 [C:Program FilesdotnetsharedMicrosoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.2.4 [C:Program FilesdotnetsharedMicrosoft.AspNetCore.App]
Microsoft.NETCore.App 1.0.4 [C:Program FilesdotnetsharedMicrosoft.NETCore.App]
Microsoft.NETCore.App 1.0.5 [C:Program FilesdotnetsharedMicrosoft.NETCore.App]
Microsoft.NETCore.App 1.1.1 [C:Program FilesdotnetsharedMicrosoft.NETCore.App]
Microsoft.NETCore.App 1.1.2 [C:Program FilesdotnetsharedMicrosoft.NETCore.App]
Microsoft.NETCore.App 2.0.0 [C:Program FilesdotnetsharedMicrosoft.NETCore.App]
Microsoft.NETCore.App 2.0.5 [C:Program FilesdotnetsharedMicrosoft.NETCore.App]
Microsoft.NETCore.App 2.1.0 [C:Program FilesdotnetsharedMicrosoft.NETCore.App]
Microsoft.NETCore.App 2.1.2 [C:Program FilesdotnetsharedMicrosoft.NETCore.App]
Microsoft.NETCore.App 2.2.2 [C:Program FilesdotnetsharedMicrosoft.NETCore.App]
Microsoft.NETCore.App 2.2.4 [C:Program FilesdotnetsharedMicrosoft.NETCore.App]

To install additional .NET Core runtimes or SDKs:
https://aka.ms/dotnet-download

VS Code version:

1.33.1

C# Extension version:

ms-vscode.csharp-1.19.0.omnisharp1.32.18

Steps to reproduce

Created a new .NET Core project based on 2.2.203
Repo that gives me issue - https://github.com/tonyranieri/omnisharp-poc

Expected behavior

I don't get the exception and the project loads.

Actual behavior

Exception when loading, no OmniSharp functionality.

Error Log

If I pin the version to 2.2.104 via the global.json and reload VS Code it works as expected.

[nguerrera]

Locatted 2 MSBuild instance(s)
            1: Visual Studio Enterprise 2017 15.4.27004.2008 - "C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\15.0\Bin"
            2: StandAlone 15.0 - "C:\Users\ranieria\.vscode\extensions\ms-vscode.csharp-1.19.0\.omnisharp\1.32.18\.msbuild\Current\Bin"

I believe it is preferring (1) over (2). @rchande is there a way to control which msbuild instance is selected? If not, you'd need to uninstall VS 2017 or install VS 2019, I guess.

[nguerrera]

Also, it's confusing that (2) is described as StandAlone 15.0 instead of StandAlone 16.0.

[filipw]

is there a way to control which msbuild instance is selected?

at the moment it's unfortunately hardcoded https://github.com/OmniSharp/omnisharp-roslyn/blob/6836fadb9c35a88d4695276d14302336a460b841/src/OmniSharp.Host/MSBuild/Discovery/MSBuildLocator.cs#L44-L50

Also, it's confusing that (2) is described as StandAlone 15.0 instead of StandAlone 16.0.

that is also currently hardcoded

[rchande]

I think @akshita31 filed a bug for us to track enabling a choice?

[themindfulcoder]

Solved this problem by adding omnisharp.json with

{
    "MsBuild": {
        "UseLegacySdkResolver": true
    }
}

[James-Lester]

@themindfulcoder Do you mean that file should be added to the project directory?

[steveoh]

So I have used a combination of items related to this issue. Not all of them are necessary to fix my issue but I will detail it anyway.

I added the MsBuild option from @themindfulcoder.

{
    "MsBuild": {
        "UseLegacySdkResolver": true
    }
}

I have a global.json pinning the sdk.

{
    "sdk": {
        "version": "2.2.300"
    }
}

I added omnishart settings to .vscode\settings.json file per @rchande in https://github.com/OmniSharp/omnisharp-vscode/issues/3102#issuecomment-500517754

{
   "omnisharp.path": "latest",
   "omnisharp.useGlobalMono": "never"
}

I added an environment variable.

export MSBuildSDKsPath=$HOME/dotnet/sdk/$(dotnet --version)/Sdks

The project

I used the dotnet new react template. It did not generate a .sln file. The existence of that file made no difference.

Once adding all of these items, the extension started to function. I started to undo what I added to see what was the real solution.

The "omnisharp.path": "latest", setting is also not required.
The "MsBuild" legacy resolver is also not required.
The env variable is not necessary

My Solution

"omnisharp.useGlobalMono": "never" is the solution to my issue on osx.

[johankvint]

My Solution

"omnisharp.useGlobalMono": "never" is the solution to my issue on osx.

@steveoh Thanks a lot dude!

[filipw]

@nguerrera @rchande I proposed a change to how we score msbuild here https://github.com/OmniSharp/omnisharp-roslyn/pull/1545
it should prevent vs2017 to be ever selected over the bundled msbuild 16 and still allow vs2019 to be used

[mdunicorn]

@James-Lester No. According to this page of Omnisharp wiki, the file omnisharp.json should be put in %USERPROFILE%/.omnisharp/.

[filipw]

the original issue reported here has been resolved as VS2017 msbuild is no longer going to be picked up.
also, Omnisharp has been updated to msbuild 16.3.

[facupm]

In C:\Users\YourUser\.omnisharp add an omnisharp.json with

{
  "MsBuild": {
  "UseLegacySdkResolver": true
  }
}