Omnisharp-roslyn: vscode/omnisharp error with sample avalonia.mvvm Todo project on linux (fedora 28)

[vphadnav]

vscode/omnisharp error referenced at https://github.com/AvaloniaUI/Avalonia/issues/2707.

[vphadnav]

reproducing the omnisharp log here in an attempt to get more views.

Starting OmniSharp server at 7/3/2019, 11:53:49 PM
    Target: /home/vphadnav/Projects/Todo

OmniSharp server started.
    Path: /home/vphadnav/.vscode/extensions/ms-vscode.csharp-1.20.0/.omnisharp/1.32.20/run
    PID: 19508

[info]: OmniSharp.Stdio.Host
        Starting OmniSharp on fedora 28.0 (x64)
[info]: OmniSharp.Services.DotNetCliService
        DotNetPath set to dotnet
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
        Located 1 MSBuild instance(s)
            1: StandAlone 15.0 - "/home/vphadnav/.vscode/extensions/ms-vscode.csharp-1.20.0/.omnisharp/1.32.20/omnisharp/.msbuild/Current/Bin"
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
        MSBUILD_EXE_PATH environment variable set to '/home/vphadnav/.vscode/extensions/ms-vscode.csharp-1.20.0/.omnisharp/1.32.20/omnisharp/.msbuild/Current/Bin/MSBuild.dll'
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
        Registered MSBuild instance: StandAlone 15.0 - "/home/vphadnav/.vscode/extensions/ms-vscode.csharp-1.20.0/.omnisharp/1.32.20/omnisharp/.msbuild/Current/Bin"
            MSBuildExtensionsPath = /home/vphadnav/.vscode/extensions/ms-vscode.csharp-1.20.0/.omnisharp/1.32.20/omnisharp/.msbuild
            BypassFrameworkInstallChecks = true
            CscToolPath = /home/vphadnav/.vscode/extensions/ms-vscode.csharp-1.20.0/.omnisharp/1.32.20/omnisharp/.msbuild/Current/Bin/Roslyn
            CscToolExe = csc.exe
            MSBuildToolsPath = /home/vphadnav/.vscode/extensions/ms-vscode.csharp-1.20.0/.omnisharp/1.32.20/omnisharp/.msbuild/Current/Bin
            TargetFrameworkRootPath = /usr/lib/mono/xbuild-frameworks
[info]: OmniSharp.Cake.CakeProjectSystem
        Detecting Cake files in '/home/vphadnav/Projects/Todo'.
[info]: OmniSharp.Cake.CakeProjectSystem
        Could not find any Cake files
[info]: OmniSharp.WorkspaceInitializer
        Project system 'OmniSharp.DotNet.DotNetProjectSystem' is disabled in the configuration.
[info]: OmniSharp.MSBuild.ProjectSystem
        No solution files found in '/home/vphadnav/Projects/Todo'
[info]: OmniSharp.MSBuild.ProjectManager
        Queue project update for '/home/vphadnav/Projects/Todo/Todo.csproj'
[info]: OmniSharp.Script.ScriptProjectSystem
        Detecting CSX files in '/home/vphadnav/Projects/Todo'.
[info]: OmniSharp.Script.ScriptProjectSystem
        Could not find any CSX files
[info]: OmniSharp.WorkspaceInitializer
        Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.CSharpWorkspaceOptionsProvider
[info]: OmniSharp.MSBuild.ProjectManager
        Loading project: /home/vphadnav/Projects/Todo/Todo.csproj
[info]: OmniSharp.WorkspaceInitializer
        Configuration finished.
[info]: OmniSharp.Stdio.Host
        Omnisharp server running using Stdio at location '/home/vphadnav/Projects/Todo' on host 19339.
[warn]: OmniSharp.MSBuild.ProjectManager
        Failed to load project file '/home/vphadnav/Projects/Todo/Todo.csproj'.
/home/vphadnav/Projects/Todo/Todo.csproj(1,1)
Microsoft.Build.Exceptions.InvalidProjectFileException: The result "" of evaluating the value "$(AvaloniaBuildTasksLocation)" of the "AssemblyFile" attribute in element <UsingTask> is not valid.  /home/vphadnav/.nuget/packages/avalonia/0.8.0/build/AvaloniaBuildTasks.targets
  at Microsoft.Build.Shared.ProjectErrorUtilities.ThrowInvalidProject (System.String errorSubCategoryResourceName, Microsoft.Build.Shared.IElementLocation elementLocation, System.String resourceName, System.Object[] args) [0x00040] in <4e0a1f1d78cf4c1ebd6f9a3dbcebf3bb>:0 
  at Microsoft.Build.Shared.ProjectErrorUtilities.VerifyThrowInvalidProject[T1,T2,T3,T4] (System.Boolean condition, System.String errorSubCategoryResourceName, Microsoft.Build.Shared.IElementLocation elementLocation, System.String resourceName, T1 arg0, T2 arg1, T3 arg2, T4 arg3) [0x00003] in <4e0a1f1d78cf4c1ebd6f9a3dbcebf3bb>:0 
  at Microsoft.Build.Shared.ProjectErrorUtilities.VerifyThrowInvalidProject[T1,T2,T3,T4] (System.Boolean condition, Microsoft.Build.Shared.IElementLocation elementLocation, System.String resourceName, T1 arg0, T2 arg1, T3 arg2, T4 arg3) [0x00000] in <4e0a1f1d78cf4c1ebd6f9a3dbcebf3bb>:0 
  at Microsoft.Build.Execution.TaskRegistry.RegisterTasksFromUsingTaskElement[P,I] (Microsoft.Build.BackEnd.Logging.ILoggingService loggingService, Microsoft.Build.Framework.BuildEventContext buildEventContext, System.String directoryOfImportingFile, Microsoft.Build.Construction.ProjectUsingTaskElement projectUsingTaskXml, Microsoft.Build.Execution.TaskRegistry taskRegistry, Microsoft.Build.Evaluation.Expander`2[P,I] expander, Microsoft.Build.Evaluation.ExpanderOptions expanderOptions, Microsoft.Build.Shared.FileSystem.IFileSystem fileSystem) [0x0011a] in <4e0a1f1d78cf4c1ebd6f9a3dbcebf3bb>:0 
  at Microsoft.Build.Evaluation.Evaluator`4[P,I,M,D].EvaluateUsingTaskElement (System.String directoryOfImportingFile, Microsoft.Build.Construction.ProjectUsingTaskElement projectUsingTaskElement) [0x00036] in <4e0a1f1d78cf4c1ebd6f9a3dbcebf3bb>:0 
  at Microsoft.Build.Evaluation.Evaluator`4[P,I,M,D].Evaluate (Microsoft.Build.BackEnd.Logging.ILoggingService loggingService, Microsoft.Build.Framework.BuildEventContext buildEventContext) [0x00372] in <4e0a1f1d78cf4c1ebd6f9a3dbcebf3bb>: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.ProjectRootElementCache projectRootElementCache, Microsoft.Build.Framework.BuildEventContext buildEventContext, Microsoft.Build.BackEnd.SdkResolution.ISdkResolverService sdkResolverService, System.Int32 submissionId, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x0002d] in <4e0a1f1d78cf4c1ebd6f9a3dbcebf3bb>:0 
  at Microsoft.Build.Evaluation.Project.Reevaluate (Microsoft.Build.BackEnd.Logging.ILoggingService loggingServiceForEvaluation, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x0005e] in <4e0a1f1d78cf4c1ebd6f9a3dbcebf3bb>:0 
  at Microsoft.Build.Evaluation.Project.ReevaluateIfNecessary (Microsoft.Build.BackEnd.Logging.ILoggingService loggingServiceForEvaluation, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x00035] in <4e0a1f1d78cf4c1ebd6f9a3dbcebf3bb>:0 
  at Microsoft.Build.Evaluation.Project.ReevaluateIfNecessary (Microsoft.Build.BackEnd.Logging.ILoggingService loggingServiceForEvaluation, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x00000] in <4e0a1f1d78cf4c1ebd6f9a3dbcebf3bb>:0 
  at Microsoft.Build.Evaluation.Project.ReevaluateIfNecessary () [0x00007] in <4e0a1f1d78cf4c1ebd6f9a3dbcebf3bb>:0 
  at OmniSharp.MSBuild.ProjectLoader.SetTargetFrameworkIfNeeded (Microsoft.Build.Evaluation.Project evaluatedProject) [0x00047] in <598756bbad7c4a61bb212e3681e5d1da>:0 
  at OmniSharp.MSBuild.ProjectLoader.EvaluateProjectFileCore (System.String filePath) [0x00047] in <598756bbad7c4a61bb212e3681e5d1da>:0 
  at OmniSharp.MSBuild.ProjectLoader.BuildProject (System.String filePath) [0x0000d] in <598756bbad7c4a61bb212e3681e5d1da>:0 
  at OmniSharp.MSBuild.ProjectFile.ProjectFileInfo.Load (System.String filePath, OmniSharp.MSBuild.ProjectIdInfo projectIdInfo, OmniSharp.MSBuild.ProjectLoader loader) [0x00015] in <598756bbad7c4a61bb212e3681e5d1da>:0 
  at OmniSharp.MSBuild.ProjectManager+<>c__DisplayClass30_0.<LoadProject>b__0 () [0x00000] in <598756bbad7c4a61bb212e3681e5d1da>: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 <598756bbad7c4a61bb212e3681e5d1da>:0 

[fail]: OmniSharp.MSBuild.ProjectManager
        Attempted to update project that is not loaded: /home/vphadnav/Projects/Todo/Todo.csproj

[SirJson]

I'm having the same issue on Arch Linux. Building the app with .NET Core works fine but OmniSharp fails to provide any auto completion.

```Starting OmniSharp server at 7/8/2019, 2:14:10 PM
Target: /home/raffa/Projects/autocrud

OmniSharp server started with Mono 5.20.1.
Path: /home/raffa/.vscode/extensions/ms-vscode.csharp-1.20.0/.omnisharp/1.32.20/omnisharp/OmniSharp.exe
PID: 6765

    Starting OmniSharp on arch 0.0 (x64)
    DotNetPath set to dotnet
    Located 2 MSBuild instance(s)
        1: Mono 15.0 - "/usr/lib/mono/msbuild/15.0/bin"
        2: StandAlone 15.0 - "/home/raffa/.vscode/extensions/ms-vscode.csharp-1.20.0/.omnisharp/1.32.20/omnisharp/.msbuild/Current/Bin"
    Registered MSBuild instance: Mono 15.0 - "/usr/lib/mono/msbuild/15.0/bin"
        CscToolExe = csc.exe
        CscToolPath = /home/raffa/.vscode/extensions/ms-vscode.csharp-1.20.0/.omnisharp/1.32.20/omnisharp/.msbuild/Current/Bin/Roslyn
    Detecting Cake files in '/home/raffa/Projects/autocrud'.
    Could not find any Cake files
    Project system 'OmniSharp.DotNet.DotNetProjectSystem' is disabled in the configuration.
    No solution files found in '/home/raffa/Projects/autocrud'
    Queue project update for '/home/raffa/Projects/autocrud/autocrud.csproj'
    Detecting CSX files in '/home/raffa/Projects/autocrud'.
    Could not find any CSX files
    Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.CSharpWorkspaceOptionsProvider
    Loading project: /home/raffa/Projects/autocrud/autocrud.csproj
    Configuration finished.
    Omnisharp server running using Stdio at location '/home/raffa/Projects/autocrud' on host 6532.
    Failed to load project file '/home/raffa/Projects/autocrud/autocrud.csproj'.

/home/raffa/Projects/autocrud/autocrud.csproj(1,1)
Microsoft.Build.Exceptions.InvalidProjectFileException: The result "" of evaluating the value "$(AvaloniaBuildTasksLocation)" of the "AssemblyFile" attribute in element is not valid. /home/raffa/.nuget/packages/avalonia/0.8.0/build/AvaloniaBuildTasks.targets
at Microsoft.Build.Shared.ProjectErrorUtilities.ThrowInvalidProject (System.String errorSubCategoryResourceName, Microsoft.Build.Shared.IElementLocation elementLocation, System.String resourceName, System.Object[] args) [0x00040] in <58f0218f988743a48dd7c84cbe933f4e>:0
at Microsoft.Build.Shared.ProjectErrorUtilities.VerifyThrowInvalidProject[T1,T2,T3,T4] (System.Boolean condition, System.String errorSubCategoryResourceName, Microsoft.Build.Shared.IElementLocation elementLocation, System.String resourceName, T1 arg0, T2 arg1, T3 arg2, T4 arg3) [0x00003] in <58f0218f988743a48dd7c84cbe933f4e>:0
at Microsoft.Build.Shared.ProjectErrorUtilities.VerifyThrowInvalidProject[T1,T2,T3,T4] (System.Boolean condition, Microsoft.Build.Shared.IElementLocation elementLocation, System.String resourceName, T1 arg0, T2 arg1, T3 arg2, T4 arg3) [0x00000] in <58f0218f988743a48dd7c84cbe933f4e>:0
at Microsoft.Build.Execution.TaskRegistry.RegisterTasksFromUsingTaskElement[P,I] (Microsoft.Build.BackEnd.Logging.ILoggingService loggingService, Microsoft.Build.Framework.BuildEventContext buildEventContext, System.String directoryOfImportingFile, Microsoft.Build.Construction.ProjectUsingTaskElement projectUsingTaskXml, Microsoft.Build.Execution.TaskRegistry taskRegistry, Microsoft.Build.Evaluation.Expander2[P,I] expander, Microsoft.Build.Evaluation.ExpanderOptions expanderOptions, Microsoft.Build.Shared.FileSystem.IFileSystem fileSystem) [0x0011a] in <58f0218f988743a48dd7c84cbe933f4e>:0 at Microsoft.Build.Evaluation.Evaluator4[P,I,M,D].EvaluateUsingTaskElement (System.String directoryOfImportingFile, Microsoft.Build.Construction.ProjectUsingTaskElement projectUsingTaskElement) [0x00036] in <58f0218f988743a48dd7c84cbe933f4e>:0
at Microsoft.Build.Evaluation.Evaluator4[P,I,M,D].Evaluate (Microsoft.Build.BackEnd.Logging.ILoggingService loggingService, Microsoft.Build.Framework.BuildEventContext buildEventContext) [0x00372] in <58f0218f988743a48dd7c84cbe933f4e>:0 at Microsoft.Build.Evaluation.Evaluator4[P,I,M,D].Evaluate (Microsoft.Build.Evaluation.IEvaluatorData4[P,I,M,D] data, Microsoft.Build.Construction.ProjectRootElement root, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings, System.Int32 maxNodeCount, Microsoft.Build.Collections.PropertyDictionary1[T] environmentProperties, Microsoft.Build.BackEnd.Logging.ILoggingService loggingService, Microsoft.Build.Evaluation.IItemFactory2[S,T] itemFactory, Microsoft.Build.Evaluation.IToolsetProvider toolsetProvider, Microsoft.Build.Evaluation.ProjectRootElementCache projectRootElementCache, Microsoft.Build.Framework.BuildEventContext buildEventContext, Microsoft.Build.BackEnd.SdkResolution.ISdkResolverService sdkResolverService, System.Int32 submissionId, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x0002d] in <58f0218f988743a48dd7c84cbe933f4e>:0 at Microsoft.Build.Evaluation.Project.Reevaluate (Microsoft.Build.BackEnd.Logging.ILoggingService loggingServiceForEvaluation, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x0005e] in <58f0218f988743a48dd7c84cbe933f4e>:0 at Microsoft.Build.Evaluation.Project.ReevaluateIfNecessary (Microsoft.Build.BackEnd.Logging.ILoggingService loggingServiceForEvaluation, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x00035] in <58f0218f988743a48dd7c84cbe933f4e>:0 at Microsoft.Build.Evaluation.Project.ReevaluateIfNecessary (Microsoft.Build.BackEnd.Logging.ILoggingService loggingServiceForEvaluation, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext) [0x00000] in <58f0218f988743a48dd7c84cbe933f4e>:0 at Microsoft.Build.Evaluation.Project.ReevaluateIfNecessary () [0x00007] in <58f0218f988743a48dd7c84cbe933f4e>:0 at OmniSharp.MSBuild.ProjectLoader.SetTargetFrameworkIfNeeded (Microsoft.Build.Evaluation.Project evaluatedProject) [0x00047] in <598756bbad7c4a61bb212e3681e5d1da>:0 at OmniSharp.MSBuild.ProjectLoader.EvaluateProjectFileCore (System.String filePath) [0x00047] in <598756bbad7c4a61bb212e3681e5d1da>:0 at OmniSharp.MSBuild.ProjectLoader.BuildProject (System.String filePath) [0x0000d] in <598756bbad7c4a61bb212e3681e5d1da>:0 at OmniSharp.MSBuild.ProjectFile.ProjectFileInfo.Load (System.String filePath, OmniSharp.MSBuild.ProjectIdInfo projectIdInfo, OmniSharp.MSBuild.ProjectLoader loader) [0x00015] in <598756bbad7c4a61bb212e3681e5d1da>:0 at OmniSharp.MSBuild.ProjectManager+<>c__DisplayClass30_0.<LoadProject>b__0 () [0x00000] in <598756bbad7c4a61bb212e3681e5d1da>:0 at (wrapper delegate-invoke) System.Func1[System.ValueTuple3[OmniSharp.MSBuild.ProjectFile.ProjectFileInfo,System.Collections.Immutable.ImmutableArray1[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 <598756bbad7c4a61bb212e3681e5d1da>:0

    Attempted to update project that is not loaded: /home/raffa/Projects/autocrud/autocrud.csproj

```

EDIT: If I had to guess I would say that OmniSharp ignores the Avalonia.props file that came with the NuGet Package.

Replacing
-> $(AvaloniaBuildTasksLocation)
with
-> $(MSBuildThisFileDirectory)\..\tools\netstandard2.0\Avalonia.Build.Tasks.dll
in
-> ~/.nuget/packages/avalonia/0.8.0/build/AvaloniaBuildTasks.targets
did the job for me.

[vphadnav]

hmm... following your lead, i pasted the contents of Avalonia.props within AvaloniaBuildTasks.targets and that did the job as well. this seems to be a sufficient work-around for now.

[Alumniminium]

Just randomly ran into the same issue, project built fine until now. The only thing I did was work on it from Windows & Visual Studio for the first time. I'm on Manjaro/Archlinux and SirJson's workaround worked for me.

[Fenex]

Same problem on Windows 7. SirJson's notes helped me.