Omnisharp-vscode: 1.21.4 breaks OmniSharp on Arch

[thatcosmonaut]

Issue Description

When the extension updated to 1.21.4, OmniSharp became unable to find my installed SDKs. Rolling back to 1.21.3 resolved the issue. dotnet-core-preview is installed from AUR. I do not have mono installed and I am not using the legacy resolver workaround.

Steps to Reproduce

Update to 1.21.4.

Expected Behavior

OmniSharp loads correctly.

Actual Behavior

OmniSharp log shows several "Could not find installed SDK" errors.

Logs

OmniSharp log

Starting OmniSharp server at 10/3/2019, 5:36:56 PM
Target: /home/cosmonaut/programming/games/SamuraiGunn2/SamuraiGunn2.sln

OmniSharp server started.
Path: /home/cosmonaut/.vscode/extensions/ms-vscode.csharp-1.21.4/.omnisharp/1.34.4/run
PID: 22218

    Starting OmniSharp on manjaro 0.0 (x64)
    DotNetPath set to dotnet
    Located 1 MSBuild instance(s)
        1: StandAlone 16.0 - "/home/cosmonaut/.vscode/extensions/ms-vscode.csharp-1.21.4/.omnisharp/1.34.4/omnisharp/.msbuild/Current/Bin"
    MSBUILD_EXE_PATH environment variable set to '/home/cosmonaut/.vscode/extensions/ms-vscode.csharp-1.21.4/.omnisharp/1.34.4/omnisharp/.msbuild/Current/Bin/MSBuild.dll'
    Registered MSBuild instance: StandAlone 16.0 - "/home/cosmonaut/.vscode/extensions/ms-vscode.csharp-1.21.4/.omnisharp/1.34.4/omnisharp/.msbuild/Current/Bin"
        MSBuildExtensionsPath = /home/cosmonaut/.vscode/extensions/ms-vscode.csharp-1.21.4/.omnisharp/1.34.4/omnisharp/.msbuild
        BypassFrameworkInstallChecks = true
        CscToolPath = /home/cosmonaut/.vscode/extensions/ms-vscode.csharp-1.21.4/.omnisharp/1.34.4/omnisharp/.msbuild/Current/Bin/Roslyn
        CscToolExe = csc.exe
        MSBuildToolsPath = /home/cosmonaut/.vscode/extensions/ms-vscode.csharp-1.21.4/.omnisharp/1.34.4/omnisharp/.msbuild/Current/Bin
    Detecting Cake files in '/home/cosmonaut/programming/games/SamuraiGunn2'.
    Could not find any Cake files
    Detecting projects in '/home/cosmonaut/programming/games/SamuraiGunn2/SamuraiGunn2.sln'.
    Queue project update for '/home/cosmonaut/programming/games/SamuraiGunn2/SamuraiGunn2/SamuraiGunn2.csproj'
    Queue project update for '/home/cosmonaut/programming/games/SamuraiGunn2/Tests/SamuraiGunn2Tests.csproj'
    Detecting CSX files in '/home/cosmonaut/programming/games/SamuraiGunn2'.
    Could not find any CSX files
    Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.CSharpFormattingWorkspaceOptionsProvider, Order: 0
    Loading project: /home/cosmonaut/programming/games/SamuraiGunn2/SamuraiGunn2/SamuraiGunn2.csproj
    Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.RenameWorkspaceOptionsProvider, Order: 100
    Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.EditorConfigWorkspaceOptionsProvider, Order: 200
    Configuration finished.
    Omnisharp server running using Stdio at location '/home/cosmonaut/programming/games/SamuraiGunn2' on host 22067.

It was not possible to find any installed .NET Core SDKs
Did you mean to run .NET Core SDK commands? Install a .NET Core SDK from:
https://aka.ms/dotnet-download
It was not possible to find any installed .NET Core SDKs
Did you mean to run .NET Core SDK commands? Install a .NET Core SDK from:
https://aka.ms/dotnet-download
Successfully loaded project file '/home/cosmonaut/programming/games/SamuraiGunn2/SamuraiGunn2/SamuraiGunn2.csproj'.
Adding project '/home/cosmonaut/programming/games/SamuraiGunn2/SamuraiGunn2/SamuraiGunn2.csproj'
Loading project: /home/cosmonaut/programming/games/SamuraiGunn2/Tests/SamuraiGunn2Tests.csproj
It was not possible to find any installed .NET Core SDKs
Did you mean to run .NET Core SDK commands? Install a .NET Core SDK from:
https://aka.ms/dotnet-download
It was not possible to find any installed .NET Core SDKs
Did you mean to run .NET Core SDK commands? Install a .NET Core SDK from:
https://aka.ms/dotnet-download
It was not possible to find any installed .NET Core SDKs
Did you mean to run .NET Core SDK commands? Install a .NET Core SDK from:
https://aka.ms/dotnet-download
It was not possible to find any installed .NET Core SDKs
Did you mean to run .NET Core SDK commands? Install a .NET Core SDK from:
https://aka.ms/dotnet-download
Successfully loaded project file '/home/cosmonaut/programming/games/SamuraiGunn2/Tests/SamuraiGunn2Tests.csproj'.
Adding project '/home/cosmonaut/programming/games/SamuraiGunn2/Tests/SamuraiGunn2Tests.csproj'
Update project: SamuraiGunn2
Update project: SamuraiGunn2Tests
SamuraiGunn2: Did not find 'Microsoft.NETCore.App.Runtime.win-x64' in lock file.
SamuraiGunn2: Did not find 'Microsoft.NETCore.App.Runtime.osx-x64' in lock file.
SamuraiGunn2: Did not find 'Microsoft.NETCore.App.Runtime.linux-x64' in lock file.
SamuraiGunn2: Did not find 'Microsoft.AspNetCore.App.Runtime.win-x64' in lock file.
SamuraiGunn2: Did not find 'Microsoft.AspNetCore.App.Runtime.osx-x64' in lock file.
SamuraiGunn2: Did not find 'Microsoft.AspNetCore.App.Runtime.linux-x64' in lock file.
SamuraiGunn2: Did not find 'Microsoft.NETCore.App.Host.win-x64' in lock file.
SamuraiGunn2: Did not find 'Microsoft.NETCore.App.Host.osx-x64' in lock file.

Environment information

VSCode version: 1.38.1
C# Extension: 1.21.3

Mono Information

OmniSharp using built-in mono

Dotnet Information

.NET Core SDK (reflecting any global.json):
Version: 3.0.100-rc1-014190
Commit: c4d43f672d

Runtime Environment:
OS Name: manjaro
OS Version:
OS Platform: Linux
RID: linux-x64
Base Path: /opt/dotnet/sdk/3.0.100-rc1-014190/

Host (useful for support):
Version: 3.0.0-rc1-19456-20
Commit: 8f5d7b1ba4

.NET Core SDKs installed:
3.0.100-rc1-014190 [/opt/dotnet/sdk]

.NET Core runtimes installed:
Microsoft.AspNetCore.App 3.0.0-rc1.19457.4 [/opt/dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 3.0.0-rc1-19456-20 [/opt/dotnet/shared/Microsoft.NETCore.App]

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

Visual Studio Code Extensions

|Extension|Author|Version|
|---|---|---|
|csharp|ms-vscode|1.21.3|
|dotnet-test-explorer|formulahendry|0.7.1|
|EditorConfig|EditorConfig|0.13.0|
|prettier-now|remimarsal|1.4.9|
|vscode-nuget-package-manager|jmrog|1.1.6|
|vscode-theme-tragedy-and-geometry|MoonsideGames|1.2.0|
|vscode-typescript-tslint-plugin|ms-vscode|1.2.2|;

[thatcosmonaut]

Ignore the "C# Extension: 1.21.3" above, I pasted it in after I rolled back

[filipw]

thanks this was already reported in https://github.com/OmniSharp/omnisharp-roslyn/issues/1610

This is a bit unfortunate but the only change from 1.21.3 -> 1.21.4 is the move from MSBuild 16.0 to 16.3, which is required for .NET Core 3.0 RTM.
It looks like the dotnet SDK tooling (msbuild and the resolver in this case) regressed in Arch Linux support.

Probably the only workaround for you now would be to install Mono 6.4.0 (a package for which may not even exist in Arch landscape at the moment?).
I think the real issue regarding MSBuild 16.3 and .NET core resolver support for Arch should be asked on https://github.com/dotnet/toolset or perhaps https://github.com/dotnet/core-sdk

cc @livarcocc @nguerrera

[thatcosmonaut]

Can confirm that we only have Mono 6.0 in Arch world right now.

[thatcosmonaut]

It looks like there are updated MSBuild-related packages in AUR, so I will try those later and report back.

[Lgmrszd]

I've encountered same issue on my system. Installed packages mono-nightly and msbuild-16-bin from AUR. As far as I know, mono-nightly is the only aur package which ships Mono with version > 6.4.0 (It is latest 6.7.0 builds). After installing both packages everything works correct!

[thatcosmonaut]

Confirmed fixed after installing msbuild-16-bin from AUR and mono 6.0 from extras.

[masaeedu]

@filipw Could you explain why installing mono is necessary here? I don't have mono installed on my system and would rather not randomly add it without understanding exactly what purpose it's serving.