the combination of VS 2019 Version 16.5.0 Preview 2.0 and .NET Core 3.1.200-preview-014883 fails dotnet build

[barrett777]

If you install VS 2019 Version 16.5.0 Preview 2.0 (Released 1/22/2020), dotnet build fails with this error. Here's a related StackOverflow question/answer on how to work around.

https://stackoverflow.com/a/59876257/1603663

I don't know if this issue is a bug in .net core, or an update required in GitVersion

C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018: System.TypeInitializationException: The type initializer for 'GitVersion.MSBuildTask.TaskProxy' threw an exception. [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:  ---> System.IO.FileNotFoundException: Could not load file or assembly 'GitVersionTask.MsBuild, Version=5.1.3.0, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified. [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018: File name: 'GitVersionTask.MsBuild, Version=5.1.3.0, Culture=neutral, PublicKeyToken=null' [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:  ---> System.IO.FileNotFoundException: Could not load file or assembly 'GitVersionTask.MsBuild, Version=5.1.3.0, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified. [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018: File name: 'GitVersionTask.MsBuild, Version=5.1.3.0, Culture=neutral, PublicKeyToken=null' [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:    at System.Reflection.RuntimeAssembly.nLoad(AssemblyName fileName, String codeBase, RuntimeAssembly assemblyContext, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, AssemblyLoadContext assemblyLoadContext) [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:    at System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, StackCrawlMark& stackMark, AssemblyLoadContext assemblyLoadContext) [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:    at System.Reflection.Assembly.Load(AssemblyName assemblyRef, StackCrawlMark& stackMark, AssemblyLoadContext assemblyLoadContext) [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:    at System.Runtime.Loader.AssemblyLoadContext.LoadFromAssemblyName(AssemblyName assemblyName) [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:    at GitVersion.MSBuildTask.LibGit2Sharp.GitLoaderContext.Load(AssemblyName assemblyName) in D:\a\1\s\src\GitVersionTask.MsBuild\LibGit2Sharp\GitLoaderContext.cs:line 30 [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:    at System.Runtime.Loader.AssemblyLoadContext.ResolveUsingLoad(AssemblyName assemblyName) [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:    at System.Runtime.Loader.AssemblyLoadContext.Resolve(IntPtr gchManagedAssemblyLoadContext, AssemblyName assemblyName) [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:  [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:  [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:    at System.Reflection.RuntimeAssembly.GetType(QCallAssembly assembly, String name, Boolean throwOnError, Boolean ignoreCase, ObjectHandleOnStack type, ObjectHandleOnStack keepAlive, ObjectHandleOnStack assemblyLoadContext) [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:    at System.Reflection.RuntimeAssembly.GetType(String name, Boolean throwOnError, Boolean ignoreCase) [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:    at System.Reflection.Assembly.GetType(String name, Boolean throwOnError) [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:    at GitVersion.MSBuildTask.TaskProxy..cctor() in D:\a\1\s\src\GitVersionTask.MsBuild\TaskProxy.cs:line 22 [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:  [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:  [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:    --- End of inner exception stack trace --- [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:    at GitVersion.MSBuildTask.Tasks.WriteVersionInfoToBuildLog.Execute() in D:\a\1\s\src\GitVersionTask.MsBuild\Tasks\WriteVersionInfoToBuildLog.cs:line 5 [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:    at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute() [ProjectFile]
C:\Users\benb\.nuget\packages\gitversiontask\5.1.3\build\GitVersionTask.targets(10,9): error MSB4018:    at Microsoft.Build.BackEnd.TaskBuilder.ExecuteInstantiatedTask(ITaskExecutionHost taskExecutionHost, TaskLoggingContext taskLoggingContext, TaskHost taskHost, ItemBucket bucket, TaskExecutionMode howToExecuteTask) [ProjectFile]```

[SeppPenner]

I can confirm that. I have the same issue now...

[SeppPenner]

@barrett777 Thanks for the link to the workaround :)

[thoemmi]

I experience the same issue with the released 3.1.200 and GitVersionTask 5.2.4. All our CI builds fail now.
Unfortunately, even a global.json with 3.1.101 does not help.

##[error]C:\Users\TeamCityTFSAgent\.nuget\packages\gitversiontask\5.2.4\build\GitVersionTask.targets(10,9): Error MSB4018: Unerwarteter Fehler bei der WriteVersionInfoToBuildLog-Aufgabe.
System.IO.FileNotFoundException: Could not load file or assembly 'GitVersionTask.MsBuild, Version=5.2.4.0, Culture=neutral, PublicKeyToken=null'. Das System kann die angegebene Datei nicht finden.
File name: 'GitVersionTask.MsBuild, Version=5.2.4.0, Culture=neutral, PublicKeyToken=null'
 ---> System.IO.FileNotFoundException: Could not load file or assembly 'GitVersionTask.MsBuild, Version=5.2.4.0, Culture=neutral, PublicKeyToken=null'. Das System kann die angegebene Datei nicht finden.
File name: 'GitVersionTask.MsBuild, Version=5.2.4.0, Culture=neutral, PublicKeyToken=null'
   at System.Reflection.RuntimeAssembly.nLoad(AssemblyName fileName, String codeBase, RuntimeAssembly assemblyContext, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, AssemblyLoadContext assemblyLoadContext)
   at System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, StackCrawlMark& stackMark, AssemblyLoadContext assemblyLoadContext)
   at System.Reflection.Assembly.Load(AssemblyName assemblyRef, StackCrawlMark& stackMark, AssemblyLoadContext assemblyLoadContext)
   at System.Runtime.Loader.AssemblyLoadContext.LoadFromAssemblyName(AssemblyName assemblyName)
   at GitVersion.MSBuildTask.LibGit2Sharp.GitLoaderContext.Load(AssemblyName assemblyName) in D:\a\GitVersion\GitVersion\src\GitVersionTask.MsBuild\LibGit2Sharp\GitLoaderContext.cs:line 29
   at System.Runtime.Loader.AssemblyLoadContext.ResolveUsingLoad(AssemblyName assemblyName)
   at System.Runtime.Loader.AssemblyLoadContext.Resolve(IntPtr gchManagedAssemblyLoadContext, AssemblyName assemblyName)


   at GitVersion.MSBuildTask.GitVersionTaskBase.Execute() in D:\a\GitVersion\GitVersion\src\GitVersionTask.MsBuild\GitVersionTaskBase.cs:line 33
   at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()
   at Microsoft.Build.BackEnd.TaskBuilder.ExecuteInstantiatedTask(ITaskExecutionHost taskExecutionHost, TaskLoggingContext taskLoggingContext, TaskHost taskHost, ItemBucket bucket, TaskExecutionMode howToExecuteTask)

[arturcic]

I noticed that as well. I'll need to find a fix for this

[thoemmi]

Neither pinning to 3.1.101 with global.json nor a downgrade of GitVersionTask to 5.1.2 does help 😕

[arturcic]

Have you upgraded the sdk on the CI to 3.1.200?

[thoemmi]

Yes, I have updated the VS Build Tools to 16.5 on our build machine an hour ago.

Our CI Build includes a build step to use .NET Core SDK 3.1.x, so it already used the latest SDK before my update 🙄

[arturcic]

Then either you downgrade the build tools to 16.4 and used sdk 3.1.102 or just wait for a fix, but it could take some time to fix it.

[thoemmi]

I've uninstalled 16.5 and installed 16.4.5 (for reference, you can get specific versions here). However, this didn't help, as each build agent has its own copy of dotnet + SDK, therefore I had to remove _tools/dotnet folder of each agent manually. Afterwards all pipelines built successfully, even with GitVersionTask 5.2.4.
I.e. the pressure is reduced 😅

[arturcic]

That's great

[rainersigwald]

This is likely a result of MSBuild changes to improve task isolation (dotnet/msbuild#4916). However, it looks like GitVersion has its own GitLoaderContext, which should have insulated you from that change.

If you're affected by this, can you try setting the environment variable MSBUILDSINGLELOADCONTEXT=1 before your build and reporting whether that helps. If it does, it's a lighter-weight workaround than downgrading to SDK 3.1.1xx.

[arturcic]

@rainersigwald setting MSBUILDSINGLELOADCONTEXT=1 helped, at least I can confirm the integration tests that test the GitVersionTask passes.

Is there a way we can enable this without setting this env variable? I'd prefer someone using the package not to set the env variable prior to build