Build error GenerateDepFiles .NET 3.0.100-preview3-010431 [OSX]

[lab7734]

Build error GenerateDepFiles .NET 3.0.100-preview3-010431 [OSX]

IDE:
Visual Studio for Mac 2019 (Preview 8.0 build 2624)

PKGS:
com.microsoft.dotnet.hostfxr.3.0.0-preview3-27503-5.component.osx.x64
com.microsoft.dotnet.sharedframework.Microsoft.NETCore.App.3.0.0-preview3-27503-5.component.osx.x64

Project:
netstandard 2.0 library

After install preview3, I'm unable to build any of my netstandard projects. All of them fails with following error:

/usr/local/share/dotnet/sdk/3.0.100-preview3-010431/Sdks/Microsoft.NET.Sdk/targets/Microsoft.NET.Sdk.targets(5,5): Error MSB4018: The "GenerateDepsFile" task failed unexpectedly.
System.TypeLoadException: Could not load type of field 'Microsoft.NET.Build.Tasks.DependencyContextBuilder:_filteredPackages' (13) due to: Could not resolve type with token 01000020 from typeref (expected class 'NuGet.Packaging.Core.PackageIdentity' in assembly 'NuGet.Packaging, Version=5.0.0.4, Culture=neutral, PublicKeyToken=31bf3856ad364e35') assembly:NuGet.Packaging, Version=5.0.0.4, Culture=neutral, PublicKeyToken=31bf3856ad364e35 type:NuGet.Packaging.Core.PackageIdentity member:(null)
at Microsoft.NET.Build.Tasks.TaskBase.Execute () [0x00000] in <9524e6fbf1724027a475d15b01fab866>:0
at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute () [0x00023] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-08/external/bockbuild/builds/msbuild-15/src/Build/BackEnd/TaskExecutionHost/TaskExecutionHost.cs:573
at Microsoft.Build.BackEnd.TaskBuilder.ExecuteInstantiatedTask (Microsoft.Build.BackEnd.ITaskExecutionHost taskExecutionHost, Microsoft.Build.BackEnd.Logging.TaskLoggingContext taskLoggingContext, Microsoft.Build.BackEnd.TaskHost taskHost, Microsoft.Build.BackEnd.ItemBucket bucket, Microsoft.Build.BackEnd.TaskExecutionMode howToExecuteTask) [0x00212] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-08/external/bockbuild/builds/msbuild-15/src/Build/BackEnd/Components/RequestBuilder/TaskBuilder.cs:784 (MSB4018)

For now, I tried to fix this error by removing all existing dotnet sdk versions by running this script. After that, I performed a reboot and reinstall preview3, same error.
The dotnet cli can build my projects with dotnet build, no errors, all fine.

[leecow]

Since you can build outside of VS for Mac using the CLI, I'm suspicious that it may be something on the VS for Mac side. Adding a few folks @livarcocc @sayedihashimi @mhutch ?

[sergiotapia]

On a simple dotnet new console -o MyApp, I can successfully:

dotnet build # for all three major platforms, Mac, Windows and Linux
dotnet run

But if I open the .csproj file in Visual Studio preview, I get build errors like OP.

[mhutch]

/cc @mrward

[mrward]

.NET Core 3 preview 3 is not supported with Mono's MSBuild currently. .NET Core 3 preview 2 should be OK.

Mono's MSBuild is currently using NuGet v4 which does not support .NET Core 3 preview 3. NuGet v5 is needed.

https://developercommunity.visualstudio.com/content/problem/481018/resolvepackageassets-task-failed.html

[karelz]

Seems to be answered above. Closing.

[sergiotapia]

So what is the solution here?

[vignatov]

I guess there is no solution. Only wait for the next MSBuild update and uninstall preview 3 till then if you need to compile.

[sergiotapia]

Thank you, just asking for would be travellers falling onto this Github issue. This issue should probably not be closed as it's not really fixed?

[karelz]

@sergiotapia please follow up with @mrward where to file the issue fo VS for Mac.

[mrward]

The issue is already filed on the Visual Studio for Mac's Developer Community - can you follow that to get updates? There should be a Follow button on the page.

https://developercommunity.visualstudio.com/content/problem/481018/resolvepackageassets-task-failed.html

[knocte]

The title of the issue should be tweaked, because it doesn't affect just .NET Core 3 anymore. I just reproduced it when my CI build pulled dotnet 2.1.602-1 (instead of 2.1.505-1 which was working fine yesterday). In my case the error is:

Error MSB4018: The "GenerateDepsFile" task failed unexpectedly. [/builds/DiginexGlobal/geewallet/src/GWallet.Backend.NetStandard/GWallet.Backend.NetStandard.fsproj]
/usr/share/dotnet/sdk/2.1.602/Sdks/Microsoft.NET.Sdk/targets/Microsoft.NET.Sdk.targets(129,5): error MSB4018: System.TypeLoadException: Could not load type of field 'Microsoft.NET.Build.Tasks.DependencyContextBuilder:_filteredPackages' (12) due to: Could not resolve type with token 01000025 from typeref (expected class 'NuGet.Packaging.Core.PackageIdentity' in assembly 'NuGet.Packaging, Version=5.0.0.6, Culture=neutral, PublicKeyToken=31bf3856ad364e35') assembly:NuGet.Packaging, Version=5.0.0.6, Culture=neutral, PublicKeyToken=31bf3856ad364e35 type:NuGet.Packaging.Core.PackageIdentity member:(null) 

I thought 2.1 was considered stable? Or is that 2.0? I'm confused.

[lytico]

same here with dotnet 2.1.602-1
and linux ubuntu 18.04

[emmakun]

Same here with current dotnet 2.2.202 on MacOS Mojave 10.14.4 with Mono 5.18.1.3