In WSL2, OmniSharp always throws "failed project load" errors when I open my dotnet/runtime repo cloned folder

## Issue Description ##

The dotnet/runtime repo has some specific build configuration, which works fine everywhere else, but not when opening the folder with VSCode via WSL2 and having OmniSharp installed.

## Steps to Reproduce ##

1. In your WSL2, clone the dotnet/runtime repo.
2. Optional: Build it using `./build.sh clr+libs -rc release`. The error shows up whether you build it or not, but this proves that the build can finish successfully, yet OmniSharp is unable to load the project correctly.
3. In VSCode, select File -> Open Folder -> Select the newly created "runtime" folder, so the project gets fully loaded by OmniSharp.
4. Look at the Output window.

## Expected Behavior ##

No errors.

## Actual Behavior ##

Project failed to load errors (see details below).

## Logs ##

Consider the fact that the runtime repo bootstraps its own build by automatically downloading the latest version of the .NET SDK, which right now is 5.0, and installs it in the folder `runtime/.dotnet`, ignoring whatever released SDK you already had installed in your WSL environment. You'll see below that 3.1 is installed, but keep in mind it's not used.

### OmniSharp log ###

```

Starting OmniSharp server at 10/29/2020, 10:29:55 AM
Target: /home/carlos/runtime/src/libraries/Microsoft.Extensions.Caching.Abstractions/Microsoft.Extensions.Caching.Abstractions.sln

OmniSharp server started.
Path: /home/carlos/.vscode-server/extensions/ms-dotnettools.csharp-1.23.4/.omnisharp/1.37.3/run
PID: 476

[info]: OmniSharp.Stdio.Host
Starting OmniSharp on ubuntu 20.4 (x64)
[info]: OmniSharp.Services.DotNetCliService
DotNetPath set to dotnet
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
Located 1 MSBuild instance(s)
1: StandAlone 16.8.0 - "/home/carlos/.vscode-server/extensions/ms-dotnettools.csharp-1.23.4/.omnisharp/1.37.3/omnisharp/.msbuild/Current/Bin"
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
MSBUILD_EXE_PATH environment variable set to '/home/carlos/.vscode-server/extensions/ms-dotnettools.csharp-1.23.4/.omnisharp/1.37.3/omnisharp/.msbuild/Current/Bin/MSBuild.exe'
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
Registered MSBuild instance: StandAlone 16.8.0 - "/home/carlos/.vscode-server/extensions/ms-dotnettools.csharp-1.23.4/.omnisharp/1.37.3/omnisharp/.msbuild/Current/Bin"
CscToolExe = csc.exe
MSBuildToolsPath = /home/carlos/.vscode-server/extensions/ms-dotnettools.csharp-1.23.4/.omnisharp/1.37.3/omnisharp/.msbuild/Current/Bin
CscToolPath = /home/carlos/.vscode-server/extensions/ms-dotnettools.csharp-1.23.4/.omnisharp/1.37.3/omnisharp/.msbuild/Current/Bin/Roslyn
BypassFrameworkInstallChecks = true
MSBuildExtensionsPath = /home/carlos/.vscode-server/extensions/ms-dotnettools.csharp-1.23.4/.omnisharp/1.37.3/omnisharp/.msbuild
[info]: OmniSharp.Cake.CakeProjectSystem
Detecting Cake files in '/home/carlos/runtime/src/libraries/Microsoft.Extensions.Caching.Abstractions'.
[info]: OmniSharp.Cake.CakeProjectSystem
Could not find any Cake files
[info]: OmniSharp.MSBuild.ProjectSystem
Detecting projects in '/home/carlos/runtime/src/libraries/Microsoft.Extensions.Caching.Abstractions/Microsoft.Extensions.Caching.Abstractions.sln'.
[info]: OmniSharp.MSBuild.ProjectManager
Queue project update for '/home/carlos/runtime/src/libraries/Microsoft.Extensions.Caching.Abstractions/ref/Microsoft.Extensions.Caching.Abstractions.csproj'
[info]: OmniSharp.MSBuild.ProjectManager
Queue project update for '/home/carlos/runtime/src/libraries/Microsoft.Extensions.Caching.Abstractions/src/Microsoft.Extensions.Caching.Abstractions.csproj'
[info]: OmniSharp.Script.ScriptProjectSystem
Detecting CSX files in '/home/carlos/runtime/src/libraries/Microsoft.Extensions.Caching.Abstractions'.
[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.WorkspaceInitializer
Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.Completion.CompletionOptionsProvider, Order: 0
[info]: OmniSharp.MSBuild.ProjectManager
Loading project: /home/carlos/runtime/src/libraries/Microsoft.Extensions.Caching.Abstractions/ref/Microsoft.Extensions.Caching.Abstractions.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/carlos/runtime/src/libraries/Microsoft.Extensions.Caching.Abstractions' on host 356.
A compatible installed .NET SDK for global.json version [5.0.100-preview.8.20417.9] from [/home/carlos/runtime/global.json] was not found.
Install the [5.0.100-preview.8.20417.9] .NET SDK or update [/home/carlos/runtime/global.json] with an installed .NET SDK:
[warn]: OmniSharp.MSBuild.ProjectManager
Failed to load project file '/home/carlos/runtime/src/libraries/Microsoft.Extensions.Caching.Abstractions/ref/Microsoft.Extensions.Caching.Abstractions.csproj'.
/home/carlos/runtime/src/libraries/Microsoft.Extensions.Caching.Abstractions/ref/Microsoft.Extensions.Caching.Abstractions.csproj(1,1)
Microsoft.Build.Exceptions.InvalidProjectFileException: The SDK 'Microsoft.NET.Sdk' specified could not be found. /home/carlos/runtime/src/libraries/Microsoft.Extensions.Caching.Abstractions/ref/Microsoft.Extensions.Caching.Abstractions.csproj
at Microsoft.Build.Shared.ProjectErrorUtilities.ThrowInvalidProject (System.String errorSubCategoryResourceName, Microsoft.Build.Shared.IElementLocation elementLocation, System.String resourceName, System.Object[] args) [0x00040] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Shared.ProjectErrorUtilities.VerifyThrowInvalidProject[T1] (System.Boolean condition, System.String errorSubCategoryResourceName, Microsoft.Build.Shared.IElementLocation elementLocation, System.String resourceName, T1 arg0) [0x00003] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Shared.ProjectErrorUtilities.ThrowInvalidProject[T1] (Microsoft.Build.Shared.IElementLocation elementLocation, System.String resourceName, T1 arg0) [0x00000] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Evaluator`4[P,I,M,D].ExpandAndLoadImportsFromUnescapedImportExpressionConditioned (System.String directoryOfImportingFile, Microsoft.Build.Construction.ProjectImportElement importElement, System.Collections.Generic.List`1[Microsoft.Build.Construction.ProjectRootElement]& projects, Microsoft.Build.BackEnd.SdkResolution.SdkResult& sdkResult, System.Boolean throwOnFileNotExistsError) [0x00309] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Evaluator`4[P,I,M,D].ExpandAndLoadImports (System.String directoryOfImportingFile, Microsoft.Build.Construction.ProjectImportElement importElement, Microsoft.Build.BackEnd.SdkResolution.SdkResult& sdkResult) [0x00027] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Evaluator`4[P,I,M,D].EvaluateImportElement (System.String directoryOfImportingFile, Microsoft.Build.Construction.ProjectImportElement importElement) [0x0000d] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Evaluator`4[P,I,M,D].PerformDepthFirstPass (Microsoft.Build.Construction.ProjectRootElement currentProjectOrImport) [0x000e6] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Evaluator`4[P,I,M,D].Evaluate () [0x00139] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Evaluator`4[P,I,M,D].Evaluate (Microsoft.Build.Evaluation.IEvaluatorData`4[P,I,M,D] data, Microsoft.Build.Construction.ProjectRootElement root, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings, System.Int32 maxNodeCount, Microsoft.Build.Collections.PropertyDictionary`1[T] environmentProperties, Microsoft.Build.BackEnd.Logging.ILoggingService loggingService, Microsoft.Build.Evaluation.IItemFactory`2[S,T] itemFactory, Microsoft.Build.Evaluation.IToolsetProvider toolsetProvider, Microsoft.Build.Evaluation.ProjectRootElementCacheBase projectRootElementCache, Microsoft.Build.Framework.BuildEventContext buildEventContext, Microsoft.Build.BackEnd.SdkResolution.ISdkResolverService sdkResolverService, System.Int32 submissionId, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext, System.Boolean interactive) [0x00047] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Project+ProjectImpl.Reevaluate (Microsoft.Build.BackEnd.Logging.ILoggingService loggingServiceForEvaluation, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x00063] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Project+ProjectImpl.ReevaluateIfNecessary (Microsoft.Build.BackEnd.Logging.ILoggingService loggingServiceForEvaluation, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x00035] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Project+ProjectImpl.ReevaluateIfNecessary (Microsoft.Build.BackEnd.Logging.ILoggingService loggingServiceForEvaluation, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x00000] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Project+ProjectImpl.ReevaluateIfNecessary (Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x00007] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Project+ProjectImpl.Initialize (System.Collections.Generic.IDictionary`2[TKey,TValue] globalProperties, System.String toolsVersion, System.String subToolsetVersion, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x00127] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Project..ctor (System.String projectFile, System.Collections.Generic.IDictionary`2[TKey,TValue] globalProperties, System.String toolsVersion, System.String subToolsetVersion, Microsoft.Build.Evaluation.ProjectCollection projectCollection, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x00073] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Project..ctor (System.String projectFile, System.Collections.Generic.IDictionary`2[TKey,TValue] globalProperties, System.String toolsVersion, System.String subToolsetVersion, Microsoft.Build.Evaluation.ProjectCollection projectCollection, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings) [0x00000] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Project..ctor (System.String projectFile, System.Collections.Generic.IDictionary`2[TKey,TValue] globalProperties, System.String toolsVersion, Microsoft.Build.Evaluation.ProjectCollection projectCollection, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings) [0x00000] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Project..ctor (System.String projectFile, System.Collections.Generic.IDictionary`2[TKey,TValue] globalProperties, System.String toolsVersion, Microsoft.Build.Evaluation.ProjectCollection projectCollection) [0x00000] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.ProjectCollection.LoadProject (System.String fileName, System.Collections.Generic.IDictionary`2[TKey,TValue] globalProperties, System.String toolsVersion) [0x000f7] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.ProjectCollection.LoadProject (System.String fileName, System.String toolsVersion) [0x00000] in <25851c819cf84f6c96378e77482fea8f>:0
at OmniSharp.MSBuild.ProjectLoader.EvaluateProjectFileCore (System.String filePath, System.Collections.Generic.IReadOnlyDictionary`2[TKey,TValue] projectConfigurationsInSolution) [0x00160] in <4b571290e6ee4e169cbb7c86cde8d5cd>:0
at OmniSharp.MSBuild.ProjectLoader.BuildProject (System.String filePath, System.Collections.Generic.IReadOnlyDictionary`2[TKey,TValue] configurationsInSolution) [0x0000d] in <4b571290e6ee4e169cbb7c86cde8d5cd>:0
at OmniSharp.MSBuild.ProjectFile.ProjectFileInfo.Load (System.String filePath, OmniSharp.MSBuild.ProjectIdInfo projectIdInfo, OmniSharp.MSBuild.ProjectLoader loader, System.Guid sessionId, OmniSharp.Services.DotNetInfo dotNetInfo) [0x00023] in <4b571290e6ee4e169cbb7c86cde8d5cd>:0
at OmniSharp.MSBuild.ProjectManager+<>c__DisplayClass31_0.b__0 () [0x00000] in <4b571290e6ee4e169cbb7c86cde8d5cd>:0
at (wrapper delegate-invoke) System.Func`1[System.ValueTuple`3[OmniSharp.MSBuild.ProjectFile.ProjectFileInfo,System.Collections.Immutable.ImmutableArray`1[OmniSharp.MSBuild.Logging.MSBuildDiagnostic],OmniSharp.MSBuild.Notification.ProjectLoadedEventArgs]].invoke_TResult()
at OmniSharp.MSBuild.ProjectManager.LoadOrReloadProject (System.String projectFilePath, System.Func`1[TResult] loader) [0x0001b] in <4b571290e6ee4e169cbb7c86cde8d5cd>:0

[info]: OmniSharp.MSBuild.ProjectManager
Loading project: /home/carlos/runtime/src/libraries/Microsoft.Extensions.Caching.Abstractions/src/Microsoft.Extensions.Caching.Abstractions.csproj
A compatible installed .NET SDK for global.json version [5.0.100-preview.8.20417.9] from [/home/carlos/runtime/global.json] was not found.
Install the [5.0.100-preview.8.20417.9] .NET SDK or update [/home/carlos/runtime/global.json] with an installed .NET SDK:
[warn]: OmniSharp.MSBuild.ProjectManager
Failed to load project file '/home/carlos/runtime/src/libraries/Microsoft.Extensions.Caching.Abstractions/src/Microsoft.Extensions.Caching.Abstractions.csproj'.
/home/carlos/runtime/src/libraries/Microsoft.Extensions.Caching.Abstractions/src/Microsoft.Extensions.Caching.Abstractions.csproj(1,1)
Microsoft.Build.Exceptions.InvalidProjectFileException: The SDK 'Microsoft.NET.Sdk' specified could not be found. /home/carlos/runtime/src/libraries/Microsoft.Extensions.Caching.Abstractions/src/Microsoft.Extensions.Caching.Abstractions.csproj
at Microsoft.Build.Shared.ProjectErrorUtilities.ThrowInvalidProject (System.String errorSubCategoryResourceName, Microsoft.Build.Shared.IElementLocation elementLocation, System.String resourceName, System.Object[] args) [0x00040] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Shared.ProjectErrorUtilities.VerifyThrowInvalidProject[T1] (System.Boolean condition, System.String errorSubCategoryResourceName, Microsoft.Build.Shared.IElementLocation elementLocation, System.String resourceName, T1 arg0) [0x00003] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Shared.ProjectErrorUtilities.ThrowInvalidProject[T1] (Microsoft.Build.Shared.IElementLocation elementLocation, System.String resourceName, T1 arg0) [0x00000] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Evaluator`4[P,I,M,D].ExpandAndLoadImportsFromUnescapedImportExpressionConditioned (System.String directoryOfImportingFile, Microsoft.Build.Construction.ProjectImportElement importElement, System.Collections.Generic.List`1[Microsoft.Build.Construction.ProjectRootElement]& projects, Microsoft.Build.BackEnd.SdkResolution.SdkResult& sdkResult, System.Boolean throwOnFileNotExistsError) [0x00309] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Evaluator`4[P,I,M,D].ExpandAndLoadImports (System.String directoryOfImportingFile, Microsoft.Build.Construction.ProjectImportElement importElement, Microsoft.Build.BackEnd.SdkResolution.SdkResult& sdkResult) [0x00027] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Evaluator`4[P,I,M,D].EvaluateImportElement (System.String directoryOfImportingFile, Microsoft.Build.Construction.ProjectImportElement importElement) [0x0000d] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Evaluator`4[P,I,M,D].PerformDepthFirstPass (Microsoft.Build.Construction.ProjectRootElement currentProjectOrImport) [0x000e6] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Evaluator`4[P,I,M,D].Evaluate () [0x00139] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Evaluator`4[P,I,M,D].Evaluate (Microsoft.Build.Evaluation.IEvaluatorData`4[P,I,M,D] data, Microsoft.Build.Construction.ProjectRootElement root, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings, System.Int32 maxNodeCount, Microsoft.Build.Collections.PropertyDictionary`1[T] environmentProperties, Microsoft.Build.BackEnd.Logging.ILoggingService loggingService, Microsoft.Build.Evaluation.IItemFactory`2[S,T] itemFactory, Microsoft.Build.Evaluation.IToolsetProvider toolsetProvider, Microsoft.Build.Evaluation.ProjectRootElementCacheBase projectRootElementCache, Microsoft.Build.Framework.BuildEventContext buildEventContext, Microsoft.Build.BackEnd.SdkResolution.ISdkResolverService sdkResolverService, System.Int32 submissionId, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext, System.Boolean interactive) [0x00047] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Project+ProjectImpl.Reevaluate (Microsoft.Build.BackEnd.Logging.ILoggingService loggingServiceForEvaluation, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x00063] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Project+ProjectImpl.ReevaluateIfNecessary (Microsoft.Build.BackEnd.Logging.ILoggingService loggingServiceForEvaluation, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x00035] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Project+ProjectImpl.ReevaluateIfNecessary (Microsoft.Build.BackEnd.Logging.ILoggingService loggingServiceForEvaluation, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x00000] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Project+ProjectImpl.ReevaluateIfNecessary (Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x00007] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Project+ProjectImpl.Initialize (System.Collections.Generic.IDictionary`2[TKey,TValue] globalProperties, System.String toolsVersion, System.String subToolsetVersion, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x00127] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Project..ctor (System.String projectFile, System.Collections.Generic.IDictionary`2[TKey,TValue] globalProperties, System.String toolsVersion, System.String subToolsetVersion, Microsoft.Build.Evaluation.ProjectCollection projectCollection, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x00073] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Project..ctor (System.String projectFile, System.Collections.Generic.IDictionary`2[TKey,TValue] globalProperties, System.String toolsVersion, System.String subToolsetVersion, Microsoft.Build.Evaluation.ProjectCollection projectCollection, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings) [0x00000] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Project..ctor (System.String projectFile, System.Collections.Generic.IDictionary`2[TKey,TValue] globalProperties, System.String toolsVersion, Microsoft.Build.Evaluation.ProjectCollection projectCollection, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings) [0x00000] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.Project..ctor (System.String projectFile, System.Collections.Generic.IDictionary`2[TKey,TValue] globalProperties, System.String toolsVersion, Microsoft.Build.Evaluation.ProjectCollection projectCollection) [0x00000] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.ProjectCollection.LoadProject (System.String fileName, System.Collections.Generic.IDictionary`2[TKey,TValue] globalProperties, System.String toolsVersion) [0x000f7] in <25851c819cf84f6c96378e77482fea8f>:0
at Microsoft.Build.Evaluation.ProjectCollection.LoadProject (System.String fileName, System.String toolsVersion) [0x00000] in <25851c819cf84f6c96378e77482fea8f>:0
at OmniSharp.MSBuild.ProjectLoader.EvaluateProjectFileCore (System.String filePath, System.Collections.Generic.IReadOnlyDictionary`2[TKey,TValue] projectConfigurationsInSolution) [0x00160] in <4b571290e6ee4e169cbb7c86cde8d5cd>:0
at OmniSharp.MSBuild.ProjectLoader.BuildProject (System.String filePath, System.Collections.Generic.IReadOnlyDictionary`2[TKey,TValue] configurationsInSolution) [0x0000d] in <4b571290e6ee4e169cbb7c86cde8d5cd>:0
at OmniSharp.MSBuild.ProjectFile.ProjectFileInfo.Load (System.String filePath, OmniSharp.MSBuild.ProjectIdInfo projectIdInfo, OmniSharp.MSBuild.ProjectLoader loader, System.Guid sessionId, OmniSharp.Services.DotNetInfo dotNetInfo) [0x00023] in <4b571290e6ee4e169cbb7c86cde8d5cd>:0
at OmniSharp.MSBuild.ProjectManager+<>c__DisplayClass31_0.b__0 () [0x00000] in <4b571290e6ee4e169cbb7c86cde8d5cd>:0
at (wrapper delegate-invoke) System.Func`1[System.ValueTuple`3[OmniSharp.MSBuild.ProjectFile.ProjectFileInfo,System.Collections.Immutable.ImmutableArray`1[OmniSharp.MSBuild.Logging.MSBuildDiagnostic],OmniSharp.MSBuild.Notification.ProjectLoadedEventArgs]].invoke_TResult()
at OmniSharp.MSBuild.ProjectManager.LoadOrReloadProject (System.String projectFilePath, System.Func`1[TResult] loader) [0x0001b] in <4b571290e6ee4e169cbb7c86cde8d5cd>:0

[fail]: OmniSharp.MSBuild.ProjectManager
Attempted to update project that is not loaded: /home/carlos/runtime/src/libraries/Microsoft.Extensions.Caching.Abstractions/ref/Microsoft.Extensions.Caching.Abstractions.csproj
[fail]: OmniSharp.MSBuild.ProjectManager
Attempted to update project that is not loaded: /home/carlos/runtime/src/libraries/Microsoft.Extensions.Caching.Abstractions/src/Microsoft.Extensions.Caching.Abstractions.csproj
```

### C# log ###

None. It's empty.

## Environment information ##

**VSCode version**: 1.50.1
**C# Extension**: 1.23.4

Mono Information
OmniSharp using built-in mono
Dotnet Information
.NET Core SDK (reflecting any global.json):
Version: 3.1.401
Commit: 39d17847db

Runtime Environment:
OS Name: ubuntu
OS Version: 20.04
OS Platform: Linux
RID: ubuntu.20.04-x64
Base Path: /usr/share/dotnet/sdk/3.1.401/

Host (useful for support):
Version: 3.1.7
Commit: fcfdef8d6b

.NET Core SDKs installed:
3.1.401 [/usr/share/dotnet/sdk]

.NET Core runtimes installed:
Microsoft.AspNetCore.App 3.1.7 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 3.1.7 [/usr/share/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|
|---|---|---|
|cpptools|ms-vscode|1.0.1|
|csharp|ms-dotnettools|1.23.4|
|gitlens|eamodio|10.2.2|
|powershell|ms-vscode|2020.6.0|
|python|ms-python|2020.10.332292344|;