Omnisharp not working in VS Code online (code spaces) for standard dotnet web api application.

[hansenms]

Issue Description

In VS Code online (codespaces), Omnisharp seems to not work anymore. It doesn't find any of the system libraries, etc:

Lot's of error messages like:

The type or namespace name 'System' could not be found (are you missing a using directive or an assembly reference?) [TestApi, TestApi]

Steps to Reproduce

1. Create a new VS code online (codespaces) instance with the standard image.
2. Create a new web api with dotnet new webapi
3. Install C# extensions
4. Open .cs file and look at the highlighting and errors.

Expected Behavior

Omnisharp and C# extensions should work out of the box.

Actual Behavior

As described above. Highlighting and intellisense does not appear to work.

Logs

OmniSharp log

Starting OmniSharp server at 7/15/2020, 4:14:17 PM
Target: /home/codespace/workspace

OmniSharp server started.
Path: /home/codespace/.vscode-remote/extensions/ms-dotnettools.csharp-1.22.1/.omnisharp/1.35.3/run
PID: 1885

Starting OmniSharp on debian 9.0 (x64)
info: OmniSharp.Services.DotNetCliService
DotNetPath set to dotnet
info: OmniSharp.MSBuild.Discovery.MSBuildLocator
Located 1 MSBuild instance(s)
1: StandAlone 16.4 - "/home/codespace/.vscode-remote/extensions/ms-dotnettools.csharp-1.22.1/.omnisharp/1.35.3/omnisharp/.msbuild/Current/Bin"
info: OmniSharp.MSBuild.Discovery.MSBuildLocator
MSBUILD_EXE_PATH environment variable set to '/home/codespace/.vscode-remote/extensions/ms-dotnettools.csharp-1.22.1/.omnisharp/1.35.3/omnisharp/.msbuild/Current/Bin/MSBuild.dll'
info: OmniSharp.MSBuild.Discovery.MSBuildLocator
Registered MSBuild instance: StandAlone 16.4 - "/home/codespace/.vscode-remote/extensions/ms-dotnettools.csharp-1.22.1/.omnisharp/1.35.3/omnisharp/.msbuild/Current/Bin"
CscToolExe = csc.exe
MSBuildToolsPath = /home/codespace/.vscode-remote/extensions/ms-dotnettools.csharp-1.22.1/.omnisharp/1.35.3/omnisharp/.msbuild/Current/Bin
CscToolPath = /home/codespace/.vscode-remote/extensions/ms-dotnettools.csharp-1.22.1/.omnisharp/1.35.3/omnisharp/.msbuild/Current/Bin/Roslyn
BypassFrameworkInstallChecks = true
MSBuildExtensionsPath = /home/codespace/.vscode-remote/extensions/ms-dotnettools.csharp-1.22.1/.omnisharp/1.35.3/omnisharp/.msbuild
info: OmniSharp.Cake.CakeProjectSystem
Detecting Cake files in '/home/codespace/workspace'.
info: OmniSharp.Cake.CakeProjectSystem
Could not find any Cake files
info: OmniSharp.MSBuild.ProjectSystem
No solution files found in '/home/codespace/workspace'
info: OmniSharp.MSBuild.ProjectManager
Queue project update for '/home/codespace/workspace/TestApi/TestApi.csproj'
info: OmniSharp.Script.ScriptProjectSystem
Detecting CSX files in '/home/codespace/workspace'.
info: OmniSharp.Script.ScriptProjectSystem
Could not find any CSX files
info: OmniSharp.WorkspaceInitializer
Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.CSharpFormattingWorkspaceOptionsProvider, Order: 0
info: OmniSharp.MSBuild.ProjectManager
Loading project: /home/codespace/workspace/TestApi/TestApi.csproj
info: OmniSharp.WorkspaceInitializer
Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.RenameWorkspaceOptionsProvider, Order: 100
info: OmniSharp.WorkspaceInitializer
Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.ImplementTypeWorkspaceOptionsProvider, Order: 110
info: OmniSharp.WorkspaceInitializer
Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.BlockStructureWorkspaceOptionsProvider, Order: 140
info: OmniSharp.WorkspaceInitializer
Configuration finished.
info: OmniSharp.Stdio.Host
Omnisharp server running using Stdio at location '/home/codespace/workspace' on host 1783.
info: OmniSharp.MSBuild.ProjectManager
Successfully loaded project file '/home/codespace/workspace/TestApi/TestApi.csproj'.
info: OmniSharp.MSBuild.ProjectManager
Adding project '/home/codespace/workspace/TestApi/TestApi.csproj'
info: OmniSharp.MSBuild.ProjectManager
Update project: TestApi

C# log

It is empty

Environment information

VSCode version: 1.45.1
C# Extension: 1.22.1

Mono Information

OmniSharp using built-in mono

Dotnet Information

.NET Core SDK (reflecting any global.json): Version: 3.1.202 Commit: 6ea70c8dca

Runtime Environment:
OS Name: debian
OS Version: 9
OS Platform: Linux
RID: debian.9-x64
Base Path: /opt/dotnet/sdks/3.1.202/sdk/3.1.202/

Host (useful for support):
Version: 3.1.4
Commit: 0c2e69caa6

.NET Core SDKs installed:
1.1.14 [/home/codespace/.dotnet/sdk]
2.1.806 [/home/codespace/.dotnet/sdk]
2.2.402 [/home/codespace/.dotnet/sdk]
3.0.103 [/home/codespace/.dotnet/sdk]
3.1.202 [/home/codespace/.dotnet/sdk]

.NET Core runtimes installed:
Microsoft.AspNetCore.All 2.2.7 [/home/codespace/.dotnet/shared/Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.2.7 [/home/codespace/.dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.0.3 [/home/codespace/.dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.4 [/home/codespace/.dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 1.1.13 [/home/codespace/.dotnet/shared/Microsoft.NETCore.App]
Microsoft.NETCore.App 2.2.7 [/home/codespace/.dotnet/shared/Microsoft.NETCore.App]
Microsoft.NETCore.App 3.0.3 [/home/codespace/.dotnet/shared/Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.4 [/home/codespace/.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-dotnettools	1.22.1
vscode-pull-request-github	GitHub	0.16.0
vsonline	ms-vsonline	1.0.2471

[JoeRobich]

@hansenms Thanks for reporting this issue. I was able to reproduce it.

From the command line the project restores and builds fine. The design time build seems to be fine because the project loads and errors are reported. But it seems the sdk reference assemblies are not being added properly to the workspace. Will need some additional investigation to determine where the issue lies.

[aaronpowell]

@JoeRobich I think this is only somewhat new (like, last week or so) as I had had it working recently but it's just stopped. Unsure if there was an omnisharp or codespaces release in that timeframe that could be a point of investigation.

[juanc5ibanez]

Hi. I have this issue as well and going to C# Extension: 1.22.0 did not help. looks like the change would be in codespaces.

[tr909jester]

Hi all,

I have a quite similar problem (but on Mac OS) and filed it at nuget, which may not be the best place it seems...
https://github.com/NuGet/docs.microsoft.com-nuget/issues/2102

Cheers,
Daniel

[Stewartarmbrecht]

Just created a new default code space. Connected via the browser. Ran the following commands:

dotnet new sln
dotnet new web
dotnet sln add workspace.csproj
dotnet restore
dotnet build

Restore and build work. IDE looks like this:

[JoeRobich]

Currently looking into this. The issue is that, during the design time build, MSBuild is not resolving Framework references in a way that our project system expects.

This is potentially an issue with the specific version of the SDK installed in the default environment.

[Stewartarmbrecht]

Is there a work around? Can we just update SDK to fix the issue?

[tr909jester]

Hi all,
see here for the solution that worked for me: #3314 (comment)
Uninstalled Mono that was installed by brew. Installed Mono from the official website => No problems any more!

[JoeRobich]

As a workaround you can enter the following into the VS Code terminal:

sudo apt install -y dotnet-sdk-3.1
rm -rf /home/codespace/.dotnet

At this point if you type dotnet --info into the terminal it will be unable to find dotnet.

Kill the terminal by clicking the trash can.

ctrl+~ (or cmd+~) to reopen the terminal.

Enter dotnet --info and you should have the 3.1.301 sdk installed.

Restart OmniSharp by pressing ctrl+p (or cmd+p) and entering >Restart Omnisharp.

OmniSharp should restart and missing type errors should be gone.

[JoeRobich]

I have opened an issue against the dev-containers - see microsoft/vscode-dev-containers#428

This issue seems to be that the .App.Ref packs are missing.

Installed on the default codespaces image:

Delivered in the Linux binaries tar.gz:

I have verified that adding only these missing pack folders fixes the issue with project loading in the C# extension.

[JoeRobich]

Closing this issue. Codespaces has updated to a newer version of the .dev-container used in the default codespaces environment with properly installed .net core SDK.

You will need to either delete and recreate your codespaces environment or follow the workaround in #3913 (comment) to install a working SDK.